Work in progress of glass panel unit and method for manufacturing glass panel unit

ABSTRACT

A work in progress includes: a pair of glass substrates arranged to face each other; a peripheral wall having a frame shape and disposed between the pair of glass substrates; a boundary wall; and an evacuation port. The boundary wall hermetically separates an internal space, surrounded with the pair of glass substrates and the peripheral wall, into an evacuation space, a buffer space, and a ventilation space. The evacuation port connects the ventilation space to an external environment. The evacuation space and the buffer space have a lower internal pressure than the ventilation space. A predetermined part, including the evacuation space but excluding parts covering the buffer space and the ventilation space, of the work in progress, forms the glass panel unit.

TECHNICAL FIELD

The present disclosure generally relates to a work in progress of a glass panel unit and a method for manufacturing the glass panel unit. More particularly, the present disclosure relates to a work in progress of a thermally insulating glass panel unit having a space between a pair of glass panels and a method for manufacturing such a glass panel unit.

BACKGROUND ART

Patent Literature 1 discloses a method for manufacturing a glass panel unit. According to the method for manufacturing a glass panel unit as taught in Patent Literature 1, an internal space surrounded with a frame member is created between a first glass substrate and a second glass substrate which are bonded together. The internal space is partitioned by a partitioning member into a first space and a second space. The air in the first space is exhausted to an external environment through an air passage, the second space, and a ventilation port to evacuate the first space to a vacuum. Thereafter, the partitioning member is melted by heating to be deformed to close the air passage. In this manner, a provisionally assembled unit with the first space that has turned into a vacuum space (i.e., a glass panel unit assembly) is obtained. Subsequently, the provisionally assembled unit is cut off and physically separated into a part having the first space and a part having the second space. The part having the first space is used as a glass panel unit.

According to Patent Literature 1, before the provisionally assembled unit is cut off, a part including the ventilation port (i.e., an evacuation port) corresponding to the part having the second space and the part having the first space that has turned into a vacuum space are present between the glass substrates. In this case, there is an internal pressure difference between the second space and the first space. Thus, while force that is going to narrow the gap between the glass substrates is applied to the first space (evacuation space), force resisting the force that is going to narrow the gap may be produced in the second space (ventilation space). This could cause damage to the glass substrates and the partitioning member (boundary walls) and eventually cause a decline in production yield.

CITATION LIST Patent Literature

Patent Literature 1 : WO 2016/143328 A1

SUMMARY OF INVENTION

The problem to overcome is to provide a work in progress of a glass panel unit and a method for manufacturing the glass panel unit, both of which contribute to increasing the production yield of the glass panel unit.

A work in progress of a glass panel unit according to an aspect of the present disclosure is used to manufacture the glass panel unit. The work in progress includes: a pair of glass substrates arranged to face each other; a peripheral wall having a frame shape and disposed between the pair of glass substrates; a boundary wall; and an evacuation port. The boundary wall is provided to hermetically separate an internal space, surrounded with the pair of glass substrates and the peripheral wall, into an evacuation space, a buffer space, and a ventilation space. The evacuation port connects the ventilation space to an external environment. The evacuation space and the buffer space have a lower internal pressure than the ventilation space. A predetermined part of the work in progress forms the glass panel unit. The predetermined part includes the evacuation space but excludes parts covering the buffer space and the ventilation space.

A method for manufacturing a glass panel unit according to another aspect of the present disclosure includes: a preparatory step of providing the work in progress of a glass panel unit described above; and a cutting step of cutting off the work in progress to obtain the predetermined part.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a plan view of a work in progress of a glass panel unit according to a first embodiment;

FIG. 2 is a cross-sectional view thereof taken along the plane A-A shown in FIG. 1;

FIG. 3 is a plan view of a glass panel unit assembly according to the first embodiment;

FIG. 4 is a cross-sectional view thereof taken along the plane B-B shown in FIG. 3;

FIG. 5 illustrates how to perform a preparatory step (assembling step) in a method for manufacturing a glass panel unit according to the first embodiment;

FIG. 6 illustrates how to perform the preparatory step (assembling step) in the manufacturing method;

FIG. 7 illustrates how to perform the preparatory step (assembling step) in the manufacturing method;

FIG. 8 illustrates how to perform the preparatory step (assembling step) in the manufacturing method;

FIG. 9 illustrates how to perform the preparatory step (assembling step) in the manufacturing method;

FIG. 10 illustrates how to perform the preparatory step (assembling step) in the manufacturing method;

FIG. 11 illustrates how to perform the preparatory step (assembling step) in the manufacturing method;

FIG. 12 illustrates how to perform the preparatory step (assembling step) in the manufacturing method;

FIG. 13 illustrates how to perform the preparatory step (assembling step) in the manufacturing method;

FIG. 14 illustrates how to perform the preparatory step (assembling step) in the manufacturing method;

FIG. 15 illustrates how to perform the preparatory step (assembling step) in the manufacturing method;

FIG. 16 illustrates how to perform the preparatory step (assembling step) in the manufacturing method;

FIG. 17 illustrates how to perform the preparatory step (assembling step) in the manufacturing method;

FIG. 18 illustrates how to perform the preparatory step (assembling step) in the manufacturing method;

FIG. 19 illustrates how to perform the preparatory step (assembling step) in the manufacturing method;

FIG. 20 illustrates how to perform the preparatory step (assembling step) in the manufacturing method;

FIG. 21 illustrates how to perform the preparatory step (assembling step) in the manufacturing method;

FIG. 22 illustrates how to perform the preparatory step (assembling step) in the manufacturing method;

FIG. 23 illustrates how to perform a removing step in the manufacturing method;

FIG. 24 is a plan view of a work in progress of a glass panel unit according to a first variation of the first embodiment;

FIG. 25 is a plan view of a glass panel unit assembly according to the first variation of the first embodiment;

FIG. 26 illustrates how to perform a preparatory step (assembling step) in a method for manufacturing a glass panel unit according to the first variation of the first embodiment;

FIG. 27 is a plan view of a glass panel unit assembly according to a second variation of the first embodiment;

FIG. 28 illustrates how to perform a preparatory step (assembling step) in a method for manufacturing a glass panel unit according to the second variation of the first embodiment;

FIG. 29 is a plan view of a glass panel unit assembly according to a third variation of the first embodiment;

FIG. 30 illustrates how to perform a preparatory step (assembling step) in a method for manufacturing a glass panel unit according to the third variation of the first embodiment;

FIG. 31 illustrates a glass panel unit assembly according to a fourth variation of the first embodiment;

FIG. 32 illustrates a glass panel unit assembly according to a fifth variation of the first embodiment;

FIG. 33 illustrates the glass panel unit assembly according to the fifth variation of the first embodiment;

FIG. 34 is a perspective view of a glass window according to a second embodiment;

FIG. 35 is an exploded perspective view of the glass window according to the second embodiment;

FIG. 36 is a plan view of the glass window according to the second embodiment;

FIG. 37 illustrates how to perform a preparatory step (assembling step) in a method for manufacturing a glass panel unit for the glass window according to the second embodiment;

FIG. 38 illustrates how to perform the preparatory step (assembling step) in the manufacturing method;

FIG. 39 illustrates how to perform the preparatory step (assembling step) in the manufacturing method;

FIG. 40 illustrates how to perform the preparatory step (assembling step) in the manufacturing method;

FIG. 41 illustrates how to perform the preparatory step (assembling step) in the manufacturing method;

FIG. 42 illustrates how to perform the preparatory step (assembling step) in the manufacturing method;

FIG. 43 shows how to perform the preparatory step (including a first melting step, an evacuation step, and a second melting step) in the manufacturing method;

FIG. 44 illustrates how to perform the preparatory step in the manufacturing method;

FIG. 45 illustrates how to perform a first cutting step in the manufacturing method;

FIG. 46 illustrates how to perform a second cutting step in the manufacturing method;

FIG. 47 is a plan view of a glass panel unit manufactured by the manufacturing method; and

FIG. 48 is a plan view of a glass window according to a variation of the second embodiment.

DESCRIPTION OF EMBODIMENTS

1. Embodiments

1.1. First Embodiment

1.1.1. Overview

FIGS. 1 and 2 illustrate a work in progress 110 of a glass panel unit according to a first exemplary embodiment. The work in progress 110 of a glass panel unit is used to manufacture one or more glass panel units (e.g., the glass panel units 10A-10H shown in FIG. 23 in this embodiment). The work in progress 110 includes a pair of glass substrates 200, 300 arranged to face each other, a peripheral wall 41, boundary walls 42 a-42 m, and an evacuation port 700 as shown in FIGS. 1 and 2. The peripheral wall 41 is arranged between the pair of glass substrates 200, 300. The peripheral wall 41 has a frame shape. The boundary walls 42 a-42 m hermetically separate an internal space 500 surrounded with the pair of glass substrates 200, 300 and the peripheral wall 41 into evacuation spaces 511 a-511 h, buffer spaces 512 a-512 f, and a ventilation space 520. The evacuation port 700 connects the ventilation space 520 to an external environment. The evacuation spaces 511 a-511 h and the buffer spaces 512 a-512 f have a lower internal pressure than the ventilation space 520. As shown in FIG. 23, a predetermined part of the work in progress 110 including the evacuation spaces 511 a-511 h but excluding parts 11 (11A, 11B) covering the buffer spaces 512 a-512 f and the ventilation space 520 forms glass panel units 10 (10A-10H).

In the work in progress 110, the buffer spaces 512 a-512 f of the parts 11A, 11B not used to form the glass panel units 10 (i.e., unnecessary parts), as well as the evacuation spaces 511 a-511 h of the glass panel units 10A-10H, have a lower internal pressure than the ventilation space 520. Thus, compared to a situation where the buffer spaces 512 a-512 f have an internal pressure equal to or higher than that of the ventilation space 520, the unbeneficial effect caused by a difference in pressure between the respective parts, corresponding to the evacuation spaces 511 a-511 h, of the pair of glass substrates 200, 300 and the rest of the glass substrates 200, 300 is reducible. This reduces the chances of the pair of glass substrates 200, 300 and the boundary walls 42 a-42 m being damaged due to the pressure difference. Thus, this work in progress 110 of glass panel units contributes to increasing the production yield of glass panel units.

1.1.2. Configuration

Next, glass panel units 10 (10A-10H), a glass panel unit assembly 100, and a work in progress 110 of glass panel units will be described in detail. The assembly 100 is used to manufacture a plurality of (e.g., eight in this example) glass panel units 10 (10A-10H) as shown in FIG. 23. The work in progress 110 is formed during the process of manufacturing the glass panel units 10 (10A-10H) out of the assembly 100. In the following description, the glass panel unit assembly 100 will be hereinafter simply referred to as an “assembly” and the work in progress 110 of glass panel units will be hereinafter simply referred to as a “work in progress” as needed.

1.1.2.1. Glass Panel Unit

First, the glass panel units 10 (10A-10H) will be described. The glass panel units 10 (10A-10H) are vacuum insulated glazing units. The vacuum insulated glazing unit is a type of multi-pane glazing unit (or multi-pane glass panel unit) including at least one pair of glass panels and has a vacuum space between the pair of glass panels. Each of the glass panel units 10A-10H includes a pair of glass panels (first and second glass panels) 20, 30, and a frame member 40 as shown in FIG. 23. In addition, each of the glass panel units 10A-10H further includes a space (evacuation space) 511 (511 a-511 h (see FIG. 1)) surrounded with the pair of glass panels 20, 30 and the frame member 40. Each of the glass panel units 10A-10H further includes, within the evacuation space 511, a gas adsorbent 60 and a plurality of pillars (spacers) 70. The glass panel units 10A-10H each have a quadrangular shape in a plan view and have the same dimensions and the same shape.

The pair of glass panels 20, 30 have the same shape, and may be each formed in a rectangular flat plate shape. Examples of materials for the pair of glass panels 20, 30 include soda lime glass, high strain point glass, chemically tempered glass, alkali-free glass, quartz glass. Neoceram, and thermally tempered glass. The surface of the pair of glass panels 20, 30 may be covered with a coating. The coating may be a transparent infrared reflective film, for example. However, this is only an example and should not be construed as limiting. The coating does not have to be an infrared reflective film but may also be any other film with desired physical properties.

The frame member 40 is arranged between the pair of glass panels 20, 30 to hermetically bond the pair of glass panels 20, 30 together. This allows an evacuation space 511, surrounded with the pair of glass panels 20, 30 and the frame member 40, to be created. In addition, the evacuation space 511 surrounded with the pair of glass panels 20, 30 and the frame member 40 is in a vacuum condition. In other words, the evacuation space 511 has an internal pressure lower than the atmospheric pressure. The frame member 40 may be made of a hot glue as a sealant. In other words, the frame member 40 is a cured hot glue. The hot glue may be a glass frit, for example. The glass fit may be a low-melting glass frit, for example. Examples of the low-melting glass frits include a bismuth-based glass frit, a lead-based glass frit, and a vanadium-based glass frit. The frame member 40, as well as the pair of glass panels 20, 30, has a polygonal shape (e.g., a quadrangular shape in this embodiment). The frame member 40 is formed along the respective outer peripheries of the pair of glass panels 20, 30. The hot glue does not have to be a glass frit but may also be a low-melting metal or a hot-melt adhesive, for example.

The gas adsorbent 60 is placed in the evacuation space 511. Specifically, the gas adsorbent 60 has an elongate flat-plate shape and is arranged on the glass panel 30. The gas adsorbent 60 is used to adsorb an unnecessary gas (such as a residual gas). The unnecessary gas is a gas emitted from the hot glue forming the frame member 40 when the hot glue is heated, for example. The gas adsorbent 60 includes a getter. The getter is a material having the property of adsorbing molecules smaller in size than a predetermined one. The getter may be an evaporative getter, for example. The evaporative getter has the property of releasing adsorbed molecules when heated to a predetermined temperature (activation temperature) or more. This allows, even if the adsorption ability of the evaporative getter deteriorates, the evaporative getter to recover its adsorption ability by being heated to the activation temperature or more. The evaporative getter may be a zeolite or an ion-exchanged zeolite (such as a copper ion exchanged zeolite). The gas adsorbent 60 includes a powder of this getter. Specifically, the gas adsorbent 60 may be formed by applying a liquid including a powder of the getter (such as a dispersion liquid obtained by dispersing a powder of the getter in a liquid or a solution obtained by dissolving a powder of the getter in a liquid) and solidifying the liquid. This reduces the size of the gas adsorbent 60, thus allowing the gas adsorbent 60 to be arranged even when the evacuation space 511 is narrow.

The plurality of pillars 70 are arranged in the evacuation space 511. The plurality of pillars 70 is used to maintain a predetermined gap between the pair of glass panels 20, 30. That is to say, the plurality of pillars 70 is used to maintain the gap distance between the pair of glass panels 20, 30 at a desired value. Note that the dimensions, number, spacing, and arrangement pattern of the pillars 70 may be selected appropriately. Each of the pillars 70 has the shape of a circular column, of which the height is approximately equal to the predetermined gap. For example, the pillars 70 may have a diameter of 1 mm and a height of 100 μm. Optionally, the pillars 70 may also have any other desired shape such as a prismatic or spherical shape.

1.1.2.2. Glass Panel Unit Assembly

Next, the glass panel unit assembly 100 will be described. As shown in FIGS. 3 and 4, the assembly 100 includes: a pair of (first and second) glass substrates 200, 300 arranged to face each other; a peripheral wall 410; first partitions 421 a-421 d and second partitions 422 a-422 j; a plurality of air passages 600; and an evacuation port 700. The assembly 100 further includes a plurality of gas adsorbents 60 and a plurality of pillars (spacers) 70. In the following description, when there is no need to distinguish the first partitions 421 a-421 d from each other, the first partitions 421 a-421 d will be hereinafter collectively referred to as “first partitions 421.” Likewise, when there is no need to distinguish the second partitions 422 a-422 j from each other, the second partitions 422 a-422 j will be hereinafter collectively referred to as “second partitions 422.” Furthermore, when there is no need to distinguish the first partitions 421 and the second partitions 422 from each other, the first partitions 421 and the second partitions 422 will be hereinafter collectively referred to as “partitions 420.”

The first glass substrate 200 is a member that forms the basis of the first glass panels 20 and is made of the same material as the first glass panels 20. The second glass substrate 300 is a member that forms the basis of the second glass panels 30 and is made of the same material as the second glass panels 30. The first and second glass substrates 200, 300 have the same shape and each have a polygonal plate shape (e.g., a rectangular plate shape in this embodiment). In this embodiment, the first glass substrate 200 has dimensions that are large enough to form the respective first glass panels 20 of the glass panel units 10A-10H, and the second glass substrate 300 has dimensions that are large enough to form the respective second glass panels 30 of the glass panel units 10A-10H.

The peripheral wall 410 is made of a sealant (first sealant). The first sealant includes a hot glue, for example. The hot glue may be a glass frit, for example. The glass frit may be a low-melting glass frit, for example. Examples of the low-melting glass frits include a bismuth-based glass frit, a lead-based glass frit, and a vanadium-based glass frit The first sealant further includes a core material. The core material is used to define the height of the frame member 40. The core material may be spherical glass heads, for example. The diameter of the glass beads may be selected according to the height of the frame member 40. Such a core material is dispersed at a predetermined ratio in the hot glue. For example, glass beads with a diameter of 50 μm to 300 μm are included to account for 0.01 wt % to 1 wt % (0.03% to 3% by volume) of the hot glue. Such a first sealant is a porous one and keeps ventilation ability before melted but loses its ventilation ability once melted.

The peripheral wall 410 is located between the pair of glass substrates 200, 300. The peripheral wall 410 has a frame shape as shown in FIG. 3. In particular, the peripheral wall 410 may have a rectangular frame shape. The peripheral wall 410 is formed along the respective outer peripheries of the first and second glass substrates 200, 300. The peripheral wall 410 has first to fourth sides 410 a-410 d. The first and second sides 410 a 410 b extend along the width of the first and second glass substrates 200, 300 (i.e., in the upward/downward direction in FIG. 3). The third and fourth sides 410 c, 410 d extend along the length of the first and second glass substrates 200, 300 (i.e., in the rightward/leftward direction in FIG. 3), The peripheral wall 410 is provided to hermetically bond the first and second glass substrates 200, 300 together. Thus, in the assembly 100, an internal space 500 is formed to be surrounded with the peripheral wall 410, the first glass substrate 200, and the second glass substrate 300.

Each of the plurality of partitions 420 is made of a sealant (second sealant). The second sealant includes a hot glue, for example. The hot glue may be a glass frit, for example. The glass frit may be a low-melting glass frit, for example. Examples of the low-melting glass frits include a bismuth-based glass frit, a lead-based glass frit, and a vanadium-based glass frit. In this embodiment, the hot glue of the partitions 420 is the same as that of the peripheral wall 410. Therefore, the partitions 420 and the peripheral wall 410 have the same softening point. In addition, the second sealant includes the same core material as the first sealant. In the second sealant, the core material is also dispersed at a predetermined ratio in the hot glue. For example, glass beads with a diameter of 50 μm to 300 μm are included to account for 0.01 wt % to 1 wt % (0.03% to 3% by volume) of the hot glue. Such a second sealant, as well as the first sealant, is a porous one and keeps ventilation ability before melted but loses its ventilation ability once melted.

The plurality of partitions 420 partitions the internal space 500 surrounded with the pair of glass substrates 200, 300 and the peripheral wall 410 into the evacuation spaces 511 (511 a-511 h), buffer spaces 512 (512 a-512 f), and the ventilation space 520. In the assembly 100, the evacuation spaces 511 a-511 h and the buffer spaces 512 a-512 f are spaces to be evacuated later (first space). The ventilation space 520 is a space (second space) for use to evacuate the first space (including the evacuation spaces 511 a-511 h and the buffer spaces 512 a-512 f). In particular, the evacuation spaces 511 a-511 h are to be evacuated to obtain glass panel units 10A-10H. On the other hand, the buffer spaces 512 a-512 f, as well as the evacuation spaces 511 a-511 h, are also evacuated for the purpose of increasing the production yield of the glass panel units 10A-10H, not to obtain the glass panel units 10A-10H.

As shown in FIG. 3, the partitions 420 are located within the area surrounded with the peripheral wall 410. Each of the partitions 420 is lower in height than the peripheral wall 410. Thus, as shown in FIG. 4, the peripheral wall 410 comes into contact with both of the first and second glass substrates 200, 300 earlier than the partitions 420 do. In the example illustrated in FIG. 3, the partitions 420 a-420 h are provided on the second glass substrate 300, and therefore, are spaced apart from the first glass substrate 200.

The plurality of partitions 420 have an elongate shape. Each partition 420 has two ends 423 (423 a, 423 b) in the length direction and two ends 424 (424 a, 424 b) in the width direction. Note that in FIG. 3, the reference signs 423 (423 a, 423 b) are added to only the second partition 422 a, and the reference signs 424 (424 a, 424 b) are added to only the first partition 421 d just for the purpose of making this drawing easily understandable. The plurality of partitions 420 includes first partitions 421 (421 a-421 d) and second partitions 422 (422 a-422 j). The respective lengths of the first partitions 421 (421 a-421 d) and second partitions 422 (422 a-422 j) are defined in two different directions. More specifically, the first partitions 421 (421 a-421 d) extend in a second direction perpendicular to a first direction in which the first and second glass substrates 200, 300 face each other. In this embodiment, the first direction is defined along the thickness of the pair of glass substrates 200, 300 (i.e., the upward/downward direction in FIG. 4). The second direction is defined along the width of the pair of glass substrates 200, 300 (i.e., the upward/downward direction in FIG. 3). The second partitions 422 (422 a-422 j) extend in a third direction perpendicular to the first direction and intersecting with the second direction. In this embodiment, the third direction is perpendicular to the second direction. The third direction is defined along the length of the pair of glass substrates 200, 300 (i.e., the rightward/leftward direction in FIG. 3).

More specifically, the first partitions 421 a, 421 b, 421 c, 421 d are elongate partitions extending along the width of the pair of glass substrates 200, 300 (i.e., the upward/downward direction in FIG. 3). In each of the first partitions 421 a, 421 b, 421 c, 421 d, one side portion 424 a thereof faces toward the first side 410 a of the peripheral wall 410 (i.e., the right side in FIG. 3) and the other side portion 424 b thereof faces toward the second side 410 b of the peripheral wall 410 (i.e., the left side in FIG. 3).

The first partitions 421 a, 421 b, 421 c, 421 d are arranged at intervals in this order from the first side 410 a of the peripheral wall 410 toward the second side 410 b thereof along the length of the pair of glass substrates 200, 300 (i.e., the rightward/leftward direction in FIG. 3). Also, none of the first partitions 421 a, 421 b, 421 c, 421 d is in contact with the third side 410 c or fourth side 410 d of the peripheral wall 410.

The second partitions 422 a-422 j are elongate partitions extending along the length of the pair of glass substrates 200, 300. In the second partitions 422 a 422 j, one end 423 a thereof is an end facing toward the first side 410 a of the peripheral wall 410 (i.e., the right side in FIG. 3) and the other end 423 b thereof is an end facing toward the second side 410 h of the peripheral wall 410 (i.e., the left side in FIG. 3).

The second partitions 422 a, 422 h are located between the second side 410 b of the peripheral wall 410 and the first partition 421 d. The second partitions 422 a, 422 b are arranged at intervals in this order from the third side 410 c of the peripheral wall 410 toward the fourth side 410 d thereof along the width of the pair of glass substrates 200, 300. The second partitions 422 a, 422 b are in contact with neither the second side 410 b of the peripheral wall 410 nor the first partition 421 d. In particular, one end 423 a of the second partitions 422 a, 422 b faces a side portion 424 b of the first partition 421 d with a predetermined gap left between them.

The second partitions 422 c, 422 d are located between the first partitions 421 c, 421 d. The second partitions 422 c, 422 d are arranged at intervals in this order from the third side 410 c of the peripheral wall 410 toward the fourth side 410 d thereof along the width of the pair of glass substrates 200, 300. The second partitions 422 c, 422 d are in contact with neither of the first partitions 421 c, 421 d. In particular, one end 423 a of the second partitions 422 c, 422 d faces a side portion 424 b of the first partition 421 c with a predetermined gap left between them. The other end 423 b of the second partitions 422 c, 422 d faces a side portion 424 a of the first partition 421 d with a predetermined gap left between them.

The second partitions 422 e, 422 f are located between the first partitions 421 b, 421 c. The second partitions 422 e, 422 f are arranged at intervals in this order from the third side 410 c of the peripheral wall 410 toward the fourth side 410 d thereof along the width of the pair of glass substrates 200, 300. The second partitions 422 e, 422 f are in contact with neither of the first partitions 421 b. 421 c. In particular, one end 423 a of the second partitions 422 e, 422 f faces a side portion 424 b of the first partition 421 b with a predetermined gap left between them. The other end 423 b of the second partitions 422 e, 422 f faces a side portion 424 a of the first partition 421 c with a predetermined gap left between them.

The second partitions 422 g, 422 h are located between the first partitions 421 a, 421 b. The second partitions 422 g, 422 h are arranged at intervals in this order from the third side 410 c of the peripheral wall 410 toward the fourth side 410 d thereof along the width of the pair of glass substrates 200, 300. The second partitions 422 g, 422 h are in contact with neither of the first partitions 421 a, 421 b, In particular, one end 423 a of the second partitions 422 g, 422 h faces a side portion 424 b of the first partition 421 a with a predetermined gap left between them. The other end 423 b of the second partitions 422 g, 422 h faces a side portion 424 a of the first partition 421 b with a predetermined gap left between them.

The second partitions 422 i, 422 j are located between the first side 410 a of the peripheral wall 410 and the first partition 421 a. The second partitions 422 i, 422 j are arranged at intervals in this order from the third side 410 c of the peripheral wall 410 toward the fourth side 410 d thereof along the width of the pair of glass substrates 200, 300. The second partitions 422 i, 422 j are in contact with neither the first side 410 a of the peripheral wall 410 nor the first partition 421 a, In particular, one end 423 b of the second partitions 422 i, 422 j faces a side portion 424 a of the first partition 421 d with a predetermined gap left between them.

In the assembly 100, the evacuation space 511 a is a space surrounded with the second and third sides 410 b, 410 c of the peripheral wall 410, the first partition 421 d, and the second partition 422 a. The evacuation space 511 b is a space surrounded with the third side 410 c of the peripheral wall 410, the first partitions 421 c, 421 d, and the second partition 422 c. The evacuation space 511 c is a space surrounded with the third side 410 c of the peripheral wall 410, the first partitions 421 b, 421 c, and the second partition 422 e. The evacuation space 511 d is a space surrounded with the third side 410 c of the peripheral wall 410, the first partitions 421 a, 421 b, and the second partition 422 g. The evacuation space 511 e is a space surrounded with the second side 410 b of the peripheral wall 410, the first partition 421 d, and the second partitions 422 a, 422 b. The evacuation space 511 f is a space surrounded with the first partitions 421 c, 421 d, and the second partitions 422 c, 422 d. The evacuation space 511 g is a space surrounded with the first partitions 421 b, 421 c, and the second partitions 422 e, 422 f. The evacuation space 511 h is a space surrounded with the first partitions 421 a, 421 b, and the second partitions 422 g, 422 h. The buffer space 512 a is a space surrounded with the first and third sides 410 a, 410 c of the peripheral wall 410, the first partition 421 a, and the second partition 422 i. The buffer space 512 b is a space surrounded with the first side 410 a of the peripheral wall 410, the first partition 421 a, and the second partitions 422 i, 422 j. The buffer space 512 c is a space surrounded with the second and fourth sides 410 b, 410 d of the peripheral wall 410, the first partition 421 d, and the second partition 422 b. The buffer space 512 d is a space surrounded with the fourth side 410 d of the peripheral wall 410, the first partitions 421 c, 421 d, and the second partition 422 d. The buffer space 512 e is a space surrounded with the fourth side 410 d of the peripheral wall 410, the first partitions 421 b, 421 c, and the second partition 422 f The buffer space 512 f is a space surrounded with the fourth side 410 d of the peripheral wall 410, the first partitions 421 a, 421 b, and the second partition 422 h. The ventilation space 520 is a space surrounded with the first and fourth sides 410 a, 410 d of the peripheral wall 410, the first partition 421 a, and the second partition 422 j.

In this embodiment, the gas adsorbent 60 is placed in only each of the evacuation spaces 511 a-511 h as shown in FIG. 3. That is to say, the gas adsorbents 60 are placed in the evacuation spaces 511 a-511 h, not in any of the buffer spaces 512 a-512 f or the ventilation space 520. Meanwhile, the plurality of pillars 70 are arranged over the entire internal space 500 (i.e., in each of the evacuation spaces 511 a-511 h, the buffer spaces 512 a-512 f, and the ventilation space 520) as shown in FIG. 1. That is to say, the plurality of pillars 70 are arranged over the evacuation spaces 511 a-511 h, the buffer spaces 512 a-512 d, and the ventilation space 520.

The plurality of air passages 600 is used to evacuate the first space (including the evacuation spaces 511 a-511 h and the buffer spaces 512 a, 512 b) through the evacuation port 700. In other words, via the plurality of air passages 600, the evacuation spaces 511 a-511 h and the buffer spaces 512 a-512 f are connected (directly or indirectly) to the ventilation space 520. In this embodiment, the peripheral wall 410 and the partitions 420 (421 a-421 h, 422 a-422 d) are arranged out of contact with each other. The respective gaps left between the peripheral wall 410 and the partitions 420 constitute the air passages 600. The respective air passages 600 are closed by melting once, and thereby deforming, the partitions 420. This allows not only at least the evacuation spaces 511 a-511 h to be (hermetically) separated from each other but also the evacuation spaces 511 a-511 h and the buffer spaces 512 a-512 f to be (hermetically) separated from the ventilation space 520 (see FIG. 1).

In this embodiment, the plurality of air passages 600 includes a plurality of particular air passages 610 which are arranged side by side in the second direction perpendicular to the first direction in Which the pair of glass substrates 200, 300 face each other. The plurality of particular air passages 610 constitute ventilation paths P10 (P10 a-P10 h) that run through the internal space 500 in the second direction (i.e., the upward/downward direction in FIG. 3). Note that in FIG. 3, the ventilation paths P10 are shaded just for the purpose of making the description easily understandable. In this embodiment, the particular air passage 610 constituting the ventilation path P10 a is a space (i.e., gap) between the respective ends 423 a of the second partitions 422 a, 422 b and the side portion 424 b of the first partition 421 d. The particular air passage 610 constituting the ventilation path P10 b is a space (i.e., gap) between the respective ends 423 b of the second partitions 422 c, 422 d and the side portion 424 a of the first partition 421 d. The particular air passage 610 constituting the ventilation path P10 c is a space (i.e., gap) between the respective ends 423 a of the second partitions 422 c, 422 d and the side portion 424 b of the first partition 421 c. The particular air passage 610 constituting the ventilation path P10 d is a space (i.e., gap) between the respective ends 423 b of the second partitions 422 e, 422 f and the side portion 424 a of the first partition 421 c. The particular air passage 610 constituting the ventilation path P10 e is a space (i.e., gap) between the respective ends 423 a of the second partitions 422 e, 422 f and the side portion 424 b of the first partition 421 b. The particular air passage 610 constituting the ventilation path P10 f is space (i.e., gap) between the respective ends 423 b of the second partitions 422 g, 422 h and the side portion 424 a of the first partition 421 b. The particular air passage 610 constituting the ventilation path P10 g is a space (i.e., gap) between the respective ends 423 a of the second partitions 422 g, 422 h and the side portion 424 b of the first partition 421 a. The particular air passage 610 constituting the ventilation path P10 h is a space (i.e., gap) between the respective ends 423 b of the second partitions 422 i, 422 j and the side portion 424 a of the first partition 421 a.

The evacuation port 700 connects the ventilation space 520 to the external environment. The evacuation port 700 is used to evacuate the evacuation spaces 511 a-511 h and the buffer spaces 512 a-512 f through the ventilation space 520 and the air passages 600. Thus, the air passages 600, the ventilation space 520, and the evacuation port 700 together form an evacuation path for evacuating the evacuation spaces 511 a-511 h and the buffer spaces 512 a-512 f. The evacuation port 700 is cut through the second glass substrate 300 to connect the ventilation space 520 to the external environment. Specifically, the evacuation port 700 is provided at a corner of the second glass substrate 300.

1.1.2.3. Work in Progress of Glass Panel Unit

Next, a work in progress 110 of glass panel units will be described. The work in progress 110 includes the pair of glass substrates (first and second glass substrates) 200, 300, a peripheral wall 41, and boundary walls 42 (42 a-42 m) as shown in FIGS. 1 and 2. In addition, the work in progress 110 further has an internal space 500 including the evacuation spaces 511 a-511 h, the buffer spaces 512 a-512 f, and the ventilation space 520. Besides, the work in progress 110 further includes gas adsorbents 60 and a plurality of pillars (spacers) 70 in the internal space 500. The work in progress 110 further has an evacuation port 700.

The peripheral wall 41 is provided between the pair of glass substrates 200, 300 to hermetically bond the pair of glass substrates 200, 300 together. The peripheral wall 41 is formed by once melting, and then solidifying again, the peripheral wall 410 of the assembly 100. Just like the peripheral wall 410 of the assembly 100, the peripheral wall 41 of the work in progress 110 also has a frame shape. In particular, the peripheral wall 41 has first to fourth sides 41 a-41 d. The first and second sides 41 a, 41 b extend along the width of the first and second glass substrates 200, 300 (i.e., in the upward/downward direction in FIG. 1). The third and fourth sides 41 c, 41 d extend along the length of the first and second glass substrates 200, 300 (i.e., the rightward/leftward direction in FIG. 1).

The boundary walls 42 a-42 m hermetically separate the internal space 500 surrounded with the pair of glass substrates 200, 300 and the peripheral wall 41 into the evacuation spaces 511 a-511 h, the buffer spaces 512 a-512 f, and the ventilation space 520. The boundary walls 42 a-42 m are formed out of the partitions 420 (421 a-421 d, 422 a-422 j). More specifically, the boundary wall 42 a linearly extends along the width of the pair of glass substrates 200, 300 to couple together the third and fourth sides 41 c, 41 d of the peripheral wall 41. The boundary wall 42 a is formed by deforming the first partition 421 a. The boundary walls 42 b-42 d are elongate walls extending along the width of the pair of glass substrates 200, 300 and are coupled to the third side 41 c of the peripheral wall 41. The boundary walls 42 b-42 d are formed by deforming the first partitions 421 b-421 d, respectively. The boundary walls 42 e, 42 f are elongate walls extending along the length of the pair of glass substrates 200, 300 to couple the second side 41 b of the peripheral wall 41 to the boundary wall 42 b. The boundary walls 42 e, 42 f are formed by deforming the second partitions 422 a, 422 b, respectively, The boundary walls 42 g, 42 h are elongate walls extending along the length of the pair of glass substrates 200, 300 to couple together the boundary walls 42 c, 42 d of the peripheral wall 41. The boundary walls 42 g, 42 h are formed by deforming the second partitions 422 c, 422 d. respectively. The boundary walls 42 i, 42 j are elongate walls extending along the length of the pair of glass substrates 200, 300 to couple together the boundary walls 42 b, 42 c of the peripheral wall 41. The boundary walls 42 i, 42 j are formed by deforming the second partitions 422 e, 422 f, respectively. The boundary walls 42 k, 42 l are elongate walls extending along the length of the pair of glass substrates 200, 300 to couple together the boundary walls 42 a, 42 b of the peripheral wall 41. The boundary walls 42 k, 42 l are formed by deforming the second partitions 422 g, 422 h, respectively. The boundary wall 42 m is an elongate wall extending along the length of the pair of glass substrates 200, 300 to couple together the first side 41 a of the peripheral wall 41 to the boundary wall 42 a thereof. The boundary wall 42 m is formed by deforming the second partition 422 j.

In particular, the boundary walls 42 a-42 m (hermetically) separate not only the evacuation spaces 511 a-511 h from each other but also the evacuation spaces 511 a-511 h and the buffer spaces 512 a-512 f from the ventilation space 520. Note that in this embodiment, the buffer spaces 512 a, 512 b are not (hermetically) separated from each other and the buffer spaces 512 c-512 f are not (hermetically) separated from each other, either. Optionally, however, the buffer spaces 512 a, 512 b may be (hermetically) separated from each other and the buffer spaces 512 c-512 f may also be (hermetically) separated from each other. That is to say, it may be determined arbitrarily whether or not the buffer spaces 512 a-512 f are (hermetically) separated from each other.

In the work in progress 110, the evacuation spaces 511 a-511 h and the buffer spaces 512 a-512 f are evacuated through the ventilation space 520 and the evacuation port 700 and have a lower internal pressure than the ventilation space 520, unlike the assembly 100. In this embodiment, the evacuation spaces 511 a-511 h and the buffer spaces 512 a-512 f are in a vacuum condition. Thus, it can be said that the evacuation spaces 511 a-511 h and the buffer spaces 512 a-512 f are vacuum spaces. As used herein, the “vacuum condition” refers to a condition with a degree of vacuum equal to or lower than a predetermined value. The predetermined value may be 0.1 Pa, for example. The evacuation spaces 511 a-511 h and the buffer spaces 512 a-512 f are perfectly closed hermetically by the first glass substrate 200, the second glass substrate 300, the peripheral wall 41, and the boundary walls 42 a-42 m, and therefore, are separated from the ventilation space 520 and the evacuation port 700.

In the work in progress 110, the evacuation space 511 a is a space surrounded with the second and third sides 41 b, 41 c of the peripheral wall 41 and the boundary walls 42 d, 42 e. The evacuation space 511 b is a space surrounded with the third side 41 c of the peripheral wall 41 and the boundary walls 42 c, 42 d, 42 g. The evacuation space 511 c is a space surrounded with the third side 41 c of the peripheral wall 41 and the boundary walls 42 b, 42 c, 42 i. The evacuation space 511 d is a space surrounded with the third side 41 c of the peripheral wall 41 and the boundary walls 42 a, 42 b, 42 k. The evacuation space 511 e is a space surrounded with the second side 41 b of the peripheral wall 41 and the boundary walls 42 d, 42 e, 42 f The evacuation space 511 f is a space surrounded with the boundary walls 42 c, 42 d, 42 g, 42 h. The evacuation space 511 g is a space surrounded with the boundary walls 42 b, 42 c, 42 i, 42 j. The evacuation space 511 h is a space surrounded with the boundary walls 42 a, 42 b, 42 k, 42 l. The buffer spaces 512 a, 512 b are spaces surrounded with the first and third sides 41 a, 41 c of the peripheral wall 41 and the boundary walls 42 a, 42 m. The buffer spaces 512 c-512 f are spaces surrounded with the second and fourth sides 41 b, 41 d of the peripheral wall 41 and the boundary walls 42 a, 42 f, 42 h, 42 j, 42 l. The ventilation space 520 is a space surrounded with the first and fourth sides 41 a, 41 d of the peripheral wall 41 and the boundary walls 42 a, 42 m.

As can be seen, the peripheral wall 41 and the boundary walls 42 a-42 m include, as their integral parts, a plurality of frame members 40 that surround the evacuation spaces 511 a-511 h. In other words, those parts, surrounding the respective evacuation spaces 511 a-511 h, of the peripheral wall 41 and the boundary walls 42 a-42 m form the frame members 40.

In the work in progress 110, the pressure inside the evacuation spaces 511 a-511 h is lower than in the ventilation space 520 including the evacuation port 700 (i.e., the atmospheric pressure). Thus, force that is going to narrow the gap between the pair of glass substrates 200, 300 is applied to the part to be used as the glass panel units 10 (10A-10H) (i.e., the evacuation spaces 511 a-511 h). Meanwhile, the pressure inside the ventilation space 520 becomes equal to the atmospheric pressure. Thus, in the ventilation space 520 that is a part not used to form the glass panel units 10 (10A-10H), force is produced which resists the force that is going to narrow the gap between the pair of glass substrates 200, 300. In this embodiment, in that part not used to form the glass panel units 10 (10A-10H), the buffer spaces 512 a-512 f are provided. In the buffer spaces 512 a-512 f, as well as in the evacuation spaces 511 a-511 h, the pressure is lower than in the ventilation space 520. Providing such buffer spaces 512 a-512 f reduces the part, of which the internal pressure is equal to the atmospheric pressure (i.e., the part that produces the force resisting the force that is going to narrow the gap between the pair of glass substrates 200, 300), in the work in progress 110. This reduces the unbeneficial effect of the difference in pressure between the part corresponding to the evacuation spaces 511 a-511 h of the pair of glass substrates 200, 300 and the rest of the pair of glass substrates 200, 300. Therefore, this reduces the chances of causing damage to the pair of glass substrates 200, 300 and the boundary walls 42 a-42 m due to such a pressure difference. Consequently, this work in progress 110 of glass panel units contributes to increasing the production yield. In this embodiment, in the work in progress 110, the ventilation space 520 is a rectangular space. For example, suppose the glass substrates 200, 300 have a longitudinal dimension of 2400 mm (the longer sides) and a lateral dimension of 1500 mm (shorter sides) just by way of example. In that case, the ventilation space 520 suitably has a lateral dimension of 500 mm or less and the ventilation space 520 suitably has an area of 250,000 mm² or less in a plan view. More suitably, the ventilation space 520 has a lateral dimension of 350 mm or less and has an area of 90,000 mm² or less in a plan view. Stated otherwise, in a plan view, the ratio of the area of the ventilation space 520 to the area of the internal space 500 is 10% or less, suitably 7% or less, more suitably 2.5% or less. In particular, the buffer spaces 512 a, 512 b are adjacent to the evacuation spaces 511 d, 511 h, respectively, and the buffer spaces 512 c-512 f are adjacent to the evacuation spaces 511 e-511 h, respectively. Therefore, particularly advantageous effects would be achieved in the evacuation spaces 511 d-511 h adjacent to the buffer spaces 512 a-512 f, respectively. In addition, the evacuation spaces 511 a-511 h are not adjacent to the ventilation space 520. This contributes to increasing the production yield of the glass panel units 10 compared to a situation where the evacuation spaces 511 a-511 h are adjacent to the ventilation space 520.

1.1.3. Manufacturing Method

Next, a method for manufacturing the glass panel units 10 (10A-10H) using the assembly 100 will be described with reference to FIGS. 3-23. This method for manufacturing the glass panel units 10 includes a preparatory step and a removing step.

The preparatory step is a step of providing the work in progress 110 shown in FIGS. 1 and 2. The preparatory step include an assembling step, a first melting step, an evacuation step, and a second melting step.

The assembling step is the step of providing the assembly 100. That is to say, the assembling step is the step of forming the first glass substrate 200, the second glass substrate 300, the peripheral wall 410, the partitions 420, the internal space 500, the air passages 600, the evacuation port 700, the plurality of gas adsorbents 60, and the plurality of pillars 70 to obtain the assembly 100. The assembling step includes first to sixth steps. Optionally, the order in which the second to fifth steps are performed may be changed as appropriate.

The first step is the step of forming the first glass substrate 200 and the second glass substrate 300 (i.e., a substrate forming step). For example, the first step includes making the first glass substrate 200 and the second glass substrate 300. If necessary, the first step may further include cleaning the first glass substrate 200 and the second glass substrate 300.

The second step is the step of forming the evacuation port 700. The second step includes cutting the evacuation port 700 through the second glass substrate 300 as shown in FIG. 5. If necessary, the second step includes cleaning the second glass substrate 300.

The third step is the step of arranging the peripheral wall 410 and the partitions 420 (including the first partitions 421 a-421 d and the second partitions 422 a-422 j) (sealant arrangement step). The third step includes a peripheral wall forming step and a partition forming step.

The peripheral wall forming step is the step of forming the peripheral wall 410. More specifically, the peripheral wall forming step is the step of forming the peripheral wall 410 by applying a material for the peripheral wall 410 (first sealant) M10 through a dispenser 810 onto one of the pair of glass substrates 200, 300 (e.g., the second glass substrate 300 in this example) as shown in FIG. 6. In the peripheral wall forming step, when the material M10 for the peripheral wall 410 is applied onto the second glass substrate 300, the material M10 for the peripheral wall 410 discharged through a nozzle 811 of the dispenser 810 is not to be pressed by the nozzle 811 as shown in FIG. 6. Then, the dispenser 810 is moved along the peripheral edges of the second glass substrate 300 (e.g., along the path T10 shown in FIG. 5) while discharging the material M10 through the nozzle 811. Thereafter, the material M10 is allowed to dry to form the peripheral wall 410, in this manner, a peripheral wall 410, of which the first to fourth sides 410 a-410 d have a height H1 and a width W1, is obtained as shown in FIG. 7. The height of the peripheral wall 410 defines the dimension of the peripheral wall 410 in the direction in which the pair of glass substrates 200, 300 face each other. In this embodiment, the height of the peripheral wall 410 is the height HI of the first to fourth sides 410 a-410 d. The height H1 and the width W1 may be adjusted according to the traveling velocity of the dispenser 810 and the rate of discharging the material M10, for example.

The partition forming step is the step of forming the first partitions 421 a-421 d and the second partitions 422 a-422 j. In the following description of the partition forming step, when there is no need to distinguish the first partitions 421 a-421 d and the second partitions 422 a-422 j from each other, the first partitions 421 a-421 d and the second partitions 422 a-422 j will be hereinafter collectively referred to “partitions 420.” This partition forming step is the step of forming the partitions 420 by applying a material (second sealant) M20 for the partitions 420 through a dispenser 820 onto one of the pair of glass substrates 200, 300 (e.g., the second glass substrate 300) as shown in FIG. 8. As can be seen, the partition forming step includes an application step of applying the material M20 for the plurality of partitions 420 onto one of the pair of glass substrates 200, 300. In this partition forming step, when the material M20 for the partitions 420 is applied onto the second glass substrate 300, the material M20 for the partitions 420 discharged through a nozzle 821 of the dispenser 820 is pressed by the nozzle 821 as shown in FIG. 8. This is done to adjust the height of the partitions 420. This allows the partitions 420 obtained to have a height H2 which is smaller than the height H1 of the peripheral wall 410 as shown in FIG. 9. The height of the partitions 420 is the dimension of the partitions 420 in the direction in which the pair of glass substrates 200, 300 face each other. The width W2 of the partitions 420 may be adjusted according to the traveling velocity of the dispenser 820 and the discharge rate of the material M20, for example. However, the range in which the width W2 is adjustable by the traveling velocity of the dispenser 820. the discharge rate of the material M20, or any other parameter has a limit. Thus, in this embodiment, to make the width W2 of the partitions 420 greater than the width of the peripheral wall 410 (i.e., the width W1 of the first to fourth sides 410 a-410 d thereof), the materials M20 for the partitions 420 are applied adjacent to one another in a direction defining the width of the partitions 420 an increased number of times. That is to say, the number of times of applying the material M20 so that the materials M20 are adjacent to one another in the direction defining the width of the partitions 420 is greater than the number of times of applying the material M10 so that the materials M10 are adjacent to one another in the direction defining the width of the peripheral wall 410 (i.e., the width of the respective sides 410 a-410 d thereof). In other words, when the partitions 420 are formed, the number of application lines is increased compared to when the peripheral wall 410 is formed.

In this embodiment, two application lines L21, L22 are formed by applying the material M20 for the partitions 420 twice in the direction defining the length of the partitions 420 so that the materials M20 are adjacent to one another in the direction defining the width of the partitions 420 as shown in FIG. 10. Specifically, the dispenser 820 is moved along the sides of quadrangles as indicated by the paths T21 a-T21 d, T22 a-T22 j as shown in FIG. 5 with the material M20 discharged through the nozzle 821. Note that the paths T21 a-T21 d correspond to the first partitions 421 a-421 d, respectively, and the paths T22 a-T22 j correspond to the second partitions 422 a-422 j, respectively. In the following description, when there is no need to distinguish the paths T21 a-T21 d from each other, the reference sign T21 will be used as needed to refer to those paths. Likewise, when there is no need to distinguish the paths T22 a-T22 j from each other, the reference sign T22 will be used as needed to refer to those paths. In this case, the interval D1 between the two adjacent application lines L21, L22 is set such that the respective surfaces of the two adjacent application lines L21, L22 are connected to be level with each other (i.e., located on the same plane). This eliminates a recess from between the respective surfaces of the adjacent application lines L21, L22. This allows a partition 420 with a flat surface to be obtained as shown in FIG. 11.

Thereafter, the material M20 is allowed to dry, thereby forming the partitions 420. In this manner, partitions 420 (421 a-421 d, 422 a-422 j) with the height H2 and the width W2 are obtained as shown in FIG. 11. As can be seen, in the partition forming step, the material M20 for the partitions 420 discharged through the nozzle 821 of the dispenser 820 is pressed with the nozzle 821 of the dispenser 820. This makes the partitions 420 lower in height than the peripheral wall 410. In addition, in the partition forming step, the number of times of applying the material M20 so that the materials M20 are adjacent to one another in the direction defining the width of the partitions 420 is larger than the number of times of applying the material M10 so that the materials M10 are adjacent to one another in the direction defining the width of the respective sides 410 a-410 d of the peripheral wall 410 as described above. This allows the partitions 420 to have a broader width than the peripheral wall 410.

In this embodiment, each of the second partitions 422 (422 a-422 j) has, at an end 423 thereof, a swollen portion 425 protruding toward both ends along the width of the second partition 422 (i.e., in the upward/downward direction in FIG. 12) as shown in FIG. 12. The swollen portion 425 has a broader width than the body (middle portion) of the second partition 422. In FIG. 12, the swollen portion 425 has a spherical shape. This swollen portion 425 makes, when a boundary wall 42 is formed by deforming the first partition 421 and the second partition 422, the angle defined by the corner portions C10 closer to the angle of intersection between the first partition 421 and the second partition 422 (e.g., 90 degrees in this embodiment) as shown in FIG. 13. Each of the corner portions C10 includes the corner of a connecting portion between a region S10 defined by the first partition 421 in the boundary wall 42 and a region S20 defined by the second partition 422 in the boundary wall 42. For example, if the second partition 422 has no swollen portions 425 at the end 423 as shown in FIG. 14, then the connecting portion between the regions S10 and S20 may have depressions as shown in FIG. 15. In that case, the angle defined by the corner portions C10 becomes significantly different from the angle of intersection between the first partition 421 and the second partition 422 (e.g., 90 degrees in this embodiment). Such depressions at the connecting portion could cause a decline in the strength of the boundary wall 42 and a decline in the appearance thereof. In this embodiment, the swollen portion 425 is provided at each of the two ends 423 of the partition 422. This reduces the chances of the partition 420 (boundary wall 42) coming to have depressions and have a decreased width in the region where the partition 420 (boundary wall 42) closes the air passage 600. This curbs a decline in the strength of the partition 420 (boundary wall 42) and contributes to increasing the production yield. In particular, this curbs a decline in the strength at the connecting portion between the regions S10, S20 of the partitions 421, 422 and a decline in appearance. Optionally, the swollen portion 425 may also be provided at each of the two ends 423 of the partition 421. This would curb a decline in strength and appearance at a connecting portion between the boundary wall 42 and the peripheral wall 41. Note that the swollen portion 425 just needs to protrude toward the evacuation space 511 at least along the width of the second partition 422. For example, if the second partition 422 is located between an evacuation space 511 and any other type of space (i.e., a buffer space 512 or the ventilation space 520), then the swollen portion 425 just needs to protrude toward the evacuation space 511 at least along the width of the second partition 422. In other words, the swollen portion 425 does not have to protrude toward the space (i.e., the buffer space 512. or the ventilation space 520) other than the evacuation space 511 along the width of the second partition 422. This is because the decline in the strength of the boundary wall 42 does not pose a significant problem in those spaces other than the evacuation space 511. Note that if the second partition 422 is located between two evacuation spaces 511, naturally the swollen portion 425 suitably protrudes toward both ends along the width of the second partition 422.

The swollen portion 425 may be formed by adjusting the velocity of the dispenser 820 traveling along the path T22 while discharging the material M20 through its nozzle 821. Specifically, the traveling velocity of the dispenser 820 applying the material M20 along one of the shorter sides of the second partition 422 (i.e., the velocity of the dispenser 820 traveling in the direction indicated by the arrow A12) may be lower than that of the dispenser 820 applying the material M20 along the longer sides of the second partition 422 (i.e., in the directions indicated by the arrows A11, A13). This allows the swollen portion 425 shown in FIG. 12 to be obtained. Suppose the traveling velocity of the dispenser 820 applying the material M20 along one of the shorter sides of the second partition 422 (i.e., the velocity of the dispenser 820 traveling in the direction indicated by the arrow A12) is set to be equal to or higher than that of the dispenser 820 applying the material M20 along the longer sides of the second partition 422 (i.e., in the directions indicated by the arrows A11, A13). In that case, a tapered end 423 with no swollen portion 425 will be obtained as shown in FIG. 14.

The fourth step is the step of forming pillars 70 (pillar forming step). The fourth step includes forming a plurality of pillars 70 in advance and placing, using a chip mounter or any other tool, the plurality of pillars 70 at predetermined positions on the second glass substrate 300. In particular, the fourth step includes placing the pillars 70 in the evacuation spaces 511 a-511 h, the buffer spaces 512 a-512 d, and the ventilation space 520. In this embodiment, the pillars 70 are lower in height than the partitions 420. Alternatively, the pillars 70 may also be formed by a combination of photolithography and etching techniques. In that case, the plurality of pillars 70 may be made of a photocurable material, for example. Still alternatively, the plurality of pillars 70 may also be formed by a known thin film forming technique.

The fifth step is the step of forming the gas adsorbents 60 (gas adsorbent forming step). The fifth step includes forming the gas adsorbents 60 by applying, using a dispenser, for example, a solution in which a powder of a getter is dispersed onto predetermined positions on the second glass substrate 300 and drying the solution. In particular, the fifth step includes arranging the gas adsorbent 60 in each of the evacuation spaces 511 a-511 h without arranging the gas adsorbent 60 in any of the buffer spaces 512 a-512 f or the ventilation space 520.

By performing these first to fifth steps, the peripheral wall 410, the partitions 420, the air passages 600, the evacuation port 700, the plurality of gas adsorbents 60, and the plurality of pillars 70 are formed on the second glass substrate 300 as shown in FIG. 16.

The sixth step is the step of arranging the first glass substrate 200 and the second glass substrate 300 (arrangement step). In the sixth step, the first glass substrate 200 and the second glass substrate 300 are arranged to be parallel to each other and face each other as shown in FIG. 16.

The assembly 100 is obtained by performing this assembling step. After the assembling step has been performed, the first melting step (bonding step), the evacuation step, and the second melting step (sealing step) are carried out.

The first melting step is the step of melting the peripheral wall 410 once to hermetically bond the pair of glass substrates 200, 300 together with the peripheral wall 410. Specifically, the first glass substrate 200 and the second glass substrate 300 are loaded into a melting furnace and heated at a first melting temperature for a predetermined amount of time (first melting time). The first melting temperature and the first melting time are set such that the first glass substrate 200 and the second glass substrate 300 are hermetically bonded together with the peripheral wall 410 but that the air passages 600 are not closed with the partitions 420. That is to say, the lower limit of the first melting temperature is the softening point of the peripheral wall 410 but the upper limit of the first melting temperature is set such that the air passages 600 are not closed with the partitions 420. For example, if the softening point of the peripheral wall 410 and the partitions 420 is 434° C., the first melting temperature may be set at 440° C. The first melting time may be 10 minutes, for example. Also, in this first melting step, the peripheral wall 410 softens too much to support the first glass substrate 200 by itself anymore, and therefore, the first glass substrate 200 is supported by the partitions 420 instead.

In this embodiment, the assembly 100 has ventilation paths P10 (P10 a-P10 h) running through the internal space 500 in the second direction (i.e., along the width of the pair of glass substrates 200, 300) as shown in FIG. 3. Thus, the first melting step includes letting hot air F10 blow in the second direction to heat the assembly 100 in the melting furnace (see FIG. 16). That is to say, the hot air F10 is allowed to pass through the ventilation paths P10 while the assembly 100 is heated. This allows the heat to be conducted sufficiently into the partitions 420 in the internal space 500 of the assembly 100, thus facilitating heating the assembly 100 (heating the partitions 420 among other things). This allows unnecessary components such as a binder included in the material (second sealant) for the partitions 420 which often emit a gas to be removed sufficiently through the first melting step. Therefore, this curbs a decline in production yield due to a gas produced from those unnecessary components, thus contributing to increasing the production yield of glass panel units.

The evacuation step is the step of evacuating the evacuation spaces 511 a-511 h and the buffer spaces 512 a-512 f through the air passages 600, the ventilation space 520, and the evacuation port 700 and thereby creating a vacuum condition in the evacuation spaces 511 a-511 h and the buffer spaces 512 a-512 f (i.e., turning these spaces into vacuum spaces). The evacuation may be carried out using a vacuum pump, for example. The vacuum pump may be connected to the assembly 100 via an evacuation pipe 830 and a sealing head 840 as shown in FIG. 16. The evacuation pipe 830 may be bonded to the second glass substrate 300 such that the inside of the evacuation pipe 830 and the evacuation port 700 communicate with each other. Bonding the evacuation pipe 830 to the glass substrate 300 may be done with an adhesive 850, for example. The adhesive 850 may be a glass frit, for example. Then, the sealing head 840 is attached to the evacuation pipe 830, thereby connecting a suction port of the vacuum pump to the evacuation port 700. The first melting step, the evacuation step, and the second inciting step are performed with the assembly 100 kept loaded in the melting furnace. Therefore, the evacuation pipe 830 is bonded to the second glass substrate 300 at least before the first melting step.

The evacuation step includes evacuating the evacuation spaces 511 a-511 h and the buffer spaces 512 a-512 f at a temperature equal to or higher than an evacuation temperature for a predetermined amount of time (evacuation time) via the air passages 600, the ventilation space 520, and the evacuation port 700 before the second melting step is started. The evacuation temperature is set at a temperature higher than the activation temperature (e.g., 350° C.) of the getter of the gas adsorbent 60 but lower than the softening point (e.g., 434° C.) of the partitions 420. The evacuation temperature may be 390° C., for example. This prevents the partitions 420 from being deformed. In addition, this causes the getter of the gas adsorbent 60 to be activated and also causes the molecules (gas) adsorbed onto the getter to be released from the getter. Then, the molecules (i.e., the gas) released from the getter are exhausted through the evacuation spaces 511 a-511 h, the buffer spaces 512 a-512 f, the air passages 600, the ventilation space 520, and the evacuation port 700. Thus, this evacuation step allows the gas adsorbent 60 to recover its adsorption ability. The evacuation time is set so as to create a vacuum space with a predetermined degree of vacuum (e.g., a degree of vacuum of 0.1 Pa or less) in the evacuation spaces 511 a-511 h and the buffer spaces 512 a-512 f. The evacuation time may be set at 120 minutes, for example.

The second melting step is the step of closing the air passages 600 by deforming the partitions 420 to form the boundary walls 42 and thereby obtain the work in progress 110. That is to say, the second melting step includes closing the air passages 600 to form a plurality of frame members 40 surrounding the evacuation spaces 511 a-511 h. As a result, as shown in FIGS. 1, 2, and 17, boundary walls 42 a-42 m are formed which hermetically separate the internal space 500 into the evacuation spaces 511 a-511 h, the buffer spaces 512 a-512 f, and the ventilation space 520. In other words, the second melting step is the step of forming the boundary walls 42 a-42 m that hermetically separate the internal space 500 into the evacuation spaces 511 a-511 h, the buffer spaces 512 a-512 f, and the ventilation space 520 by deforming the partitions 420 to close the air passages 600. Note that in the second melting step, the partitions 420 soften too much to support the first glass substrate 200 by themselves anymore, and therefore, the first glass substrate 200 is supported by the pillars 70 instead.

More specifically, inciting the partitions 420 once at a predetermined temperature (second melting temperature) equal to or higher than the softening point of the partitions 420 causes the partitions 420 to be deformed. Specifically, the first glass substrate 200 and the second glass substrate 300 are heated in the melting furnace at a second melting temperature for a predetermined amount of time (second melting time). The second melting temperature and the second melting time are set such that the partitions 420 are softened to close the air passages 600. The lower limit of the second melting temperature is the softening point (of 434° C., for example) of the partitions 420. The second melting temperature may be set at 460° C., for example. Also, the second melting time may be 30 minutes, for example.

In addition, in the second melting step, the internal space 500 continues to be evacuated. That is to say, the second melting step includes forming the boundary walls 42 a-42 m that close the air passages 600 by deforming the partitions 420 at the second melting temperature While evacuating the evacuation spaces 511 a-511 h and the buffer spaces 512 a-512 f via the air passages 600, the ventilation space 520, and the evacuation port 700. This further reduces the chances of the degree of vacuum in the evacuation spaces 511 a-511 h and the buffer spaces 512 a-512 f decreasing during the second melting step. Nevertheless, in the second melting step, the internal space 500 does not have to be evacuated continuously. Optionally, the second melting step may also be the step of closing, by deforming the partitions 420, all of the plurality of air passages 600 but at least the air passages 600 that connect the buffer spaces 512 a-512 f. That is to say, the air passages 600 between the buffer spaces 512 a-512 f do not have to be closed. Nevertheless, the air passages 600 between the buffer spaces 512 a-512 f may also be closed along with the other air passages 600.

The sealing step includes removing the evacuation pipe 830 after having formed the boundary walls 42. To remove the evacuation pipe 830, the evacuation pipe 830 is removed with a bonding portion 831 adhered to the glass substrate 300 left, and then the bonding portion 831 is scraped off. More specifically, first, impact is applied by a relatively hard object 860 to the evacuation pipe 830 as shown in FIG. 18 to break the evacuation pipe 830, and then the evacuation pipe 830 is removed with the bonding portion 831 left as shown in FIG. 19. The impact is suitably applied by the object 860 to the evacuation pipe 830 gently enough to prevent the pair of glass substrates 200, 300 from breaking. Next, the bonding portion 831 of the evacuation pipe 830, as well as the adhesive 850, is scraped off by a grinder 870 as shown in FIG. 19. In this manner, the evacuation pipe 830 is removed from the glass substrate 300 as shown in FIG. 20. In this case, the region surrounding the evacuation port 700 of the glass substrate 300 is not a mirror surface but a rough surface R10. The rough surface R10 may be regarded as showing the traces of the bonding portion 831 of the evacuation pipe 830 being scraped off by the grinder 870 or any other tool. In this case, the evacuation pipe 830 could be removed along with the adhesive 850 by the object 860 without using the grinder 870 as shown in FIG. 21. However, to remove the evacuation pipe 830 along with the adhesive 850 using the object 860, greater impact should be applied compared to breaking the evacuation pipe 830 only, thus increasing the chances of the pair of glass substrates 200, 300 breaking. In addition, in that case, the adhesive 850 could not be removed completely but a residue R20 of the adhesive 850 would be left around the evacuation port 700 of the glass substrate 300 as shown in FIG. 22. Such a residue R20 would protrude from the surface of the glass substrate 300, and therefore, might pose an obstacle to transportation of the work in progress 110, for example. For example, when a plurality of works in progress 110 are going to be piled one on top of another during the transportation of the plurality of works in progress 110, the residue R20 might pose an obstacle by coming into contact with other works in progress 110 or could cause damage to the other works in progress 110. In contrast, the method shown in FIGS. 18-20 not only reduces the impact applied by the object 860 but also leaves no residues R20. This reduces the chances of the glass substrates 200, 300 breaking and facilitates the transportation of the works in progress 110 as well.

By performing the preparatory step, the work in progress 110 shown in FIGS. 3, 4, and 17 is obtained. In the work in progress 110, the peripheral wall 410 and the partitions 420 are once melted in the first melting step and the second melting step. Thus, the gap between the pair of glass substrates 200, 300 is defined by the pillars 70, not the peripheral wall 410. Although the partitions 420 and the peripheral wall 410 have different heights, the same core material is dispersed in the first sealant and the second sealant. Thus, the peripheral wall 41 and the boundary walls 42 to be formed out of the partitions 420 and the peripheral wall 410 will have the same height. This allows the frame members 40 to have a uniform height.

The removing step is performed after the preparatory step have been performed. The removing step is the step of obtaining glass panel units 10A-10H out of the work in progress 110. The removing step is the step of obtaining glass panel units 10A-10H as parts including the evacuation spaces 511 a-511 h, respectively, by removing parts 11 (11A, 11B) including the buffer spaces 512 a-512 f and the ventilation space 520. That is to say, the removing step includes cutting off the work in progress 110 into the glass panel units 10A-10H. In the work in progress 110, the glass panel units 10A-10H form integral parts thereof. Thus, the glass panel units 10A-10H are separated from each other by cutting off the work in progress 110. For example, as shown in FIG. 1, the work in progress 110 (in particular, the glass substrates 200, 300) may be cut off along the cutting lines 900 aligned with the boundary walls 42. In this embodiment, the plurality of pillars 70 are arranged over the entire internal space 500 (in each of the evacuation spaces 511 a-511 h, the buffer spaces 512 a-512 d, and the ventilation space 520). This allows the stress applied to the pair of glass substrates 200, 300 while the work in progress 110 is being cut off to be uniformly distributed by the plurality of pillars 70, thus reducing the chances of causing damage to the pair of glass substrates 200, 300 or causing cutting failures.

By performing the removing step described above, glass panel units 10A-10H are obtained from the work in progress 110 as shown in FIG. 23. At this time, a part 11 (11A) including the buffer spaces 512 a, 512 b and the ventilation space 520 and another part 11 (11B) including the buffer spaces 512 c-512 f are obtained but are not used.

1.2. Second Embodiment

1.2.1. Background

The disclosure about a second exemplary embodiment relates to a glass window and a method for manufacturing a glass panel unit. More particularly, the disclosure about the second embodiment relates to a glass window including a glass panel unit in which a space is left between a pair of glass panels and a method for manufacturing such a glass panel unit.

JP 2016-108799 A discloses a method for manufacturing a glass panel unit in which a vacuum space is created between pair of glass panels. According to this manufacturing method, a first glass substrate and a second glass substrate are arranged to face each other with a frame member interposed between them, and then the frame member is heated and melted, thereby hermetically bonding the first glass substrate and the second glass substrate together. Subsequently, the internal space formed between the first glass substrate and the second glass substrate is evacuated to create a vacuum space there. Thereafter, the vacuum space is hermetically sealed to obtain an assembly. Then, part of the assembly is cut out as a glass panel unit.

In the glass panel unit disclosed in JP 2016-108799 A, a vacuum space is created between the pair of glass panels. Thus, in a glass window using such a glass panel unit, as the difference between the temperature of the outdoor air and room temperature increases, one of the pair of glass panels tends to warp more significantly with respect to the other glass panel. That is why a glass window using such a glass panel unit could be affected by the warpage of glass due to heat.

Thus, the problem to overcome is to provide a glass window and a method for manufacturing a glass panel unit, both of which are able to reduce the unbeneficial effect of the glass warpage due to heat.

A glass window according to an aspect of the disclosure about the second embodiment includes a glass panel unit and a window frame. The glass panel unit has a polygonal shape and includes: a pair of glass panels arranged to face each other; and a frame member arranged between the pair of glass panels to hermetically bond the pair of glass panels together. The window frame has a polygonal shape and surrounds an outer periphery of the glass panel unit. The glass panel unit has a plurality of side surfaces including at least one facing surface that faces any one of a plurality of corners of the outer periphery of the window frame.

A method for manufacturing a glass panel unit according to an aspect of the disclosure about the second embodiment includes preparatory step, a first cutting step, and a second cutting step. The preparatory step include providing a work in progress including: a pair of glass substrates arranged to face each other; and a polygonal frame member arranged between the pair of glass substrates to hermetically bond the pair of glass substrates together. The first cutting step includes cutting the work in progress along a polygon circumscribed about the frame member to obtain a predetermined part including the frame member. The second cutting step includes cutting the predetermined part along the outer periphery of the frame member to obtain the glass panel unit including the frame member and respective parts corresponding to the frame member of the pair of glass substrates.

1.2.2. Overview

FIG. 34 illustrates a glass window 1010 according to the second embodiment. The glass window 1010 includes a glass panel unit 1011 and a window frame 1012. As shown in FIG. 35, the glass panel unit 1011 includes: a pair of glass panels 1020, 1030 arranged to face each other; and a frame member 1040 arranged between the pair of glass panels 1020, 1030 to hermetically bond the pair of glass panels 1020, 1030 together. The glass panel unit 1011 has a polygonal shape. The window frame 1012 surrounds an outer periphery of the glass panel unit 1011 and has a polygonal shape. The glass panel unit 1011 has a plurality of side surfaces 1011 a-1011 h. As shown in FIG. 36, the plurality of side surfaces 1011 a-1011 h includes at least one facing surface 1011 b, 1011 d, 1011 f, 1011 h that faces any one of a plurality of corners 1012 a-1012 d of the outer periphery of the window frame 1012.

The stress caused by the warpage of the glass panels due to heat tends to be concentrated at the comers of the glass window 1010. However, the plurality of side surfaces 1011 a-1011 h of the glass panel unit 1011 includes at least one facing surface 1011 b, 1011 d, 1011 f, 1011 h that faces any one of a plurality of corners 1012 a-1012 d of the outer periphery of the window frame 1012. Therefore, the glass panel unit 1011 does not have a corner in at least one of its parts facing the corners 1012 a-1012 d of the outer periphery of the window frame 1012. This reduces the stress applied to the corners of the glass window 1010. This allows the glass window 1010 to reduce the unbeneficial effect of the warpage of the glass panels due to heat.

1.2.3. Configuration

Next, the glass window 1010 will be described in further detail. As shown in FIGS. 34-36, the glass window 1010 includes the glass panel unit 1011 and the window frame 1012.

The glass panel unit 1011 is a vacuum insulated glazing unit. The vacuum insulated glazing unit is a type of multi-pane glazing unit (or multi-pane glass panel unit) including at least one pair of glass panels and has a vacuum space between the pair of glass panels.

The glass panel unit 1011 has a polygonal shape. That is to say, the glass panel unit 1011 is polygonal in a plan view. In particular, the glass panel unit 1011 has the shape of a polygon with five or more sides. In this embodiment, the glass panel unit 1011 has the shape of an octagon having eight sides in a plan view. This glass panel unit 1011 has such a shape as the one obtained by cutting off the four corners of a square plate. The glass panel unit 1011 has a plurality of (e.g., eight in this embodiment) side surfaces 1011 a-1011 h. These eight side surfaces 1011 a-1011 h respectively correspond to the eight sides of the glass panel unit 1011 in a plan view in this case, the side surfaces 1011 a, 1011 c, 1011 e, 1011 g have an equal length. Likewise, the side surfaces 1011 b, 1011 d, 1011 f, 1011 h also have an equal length. Nevertheless, the length of the side surfaces 1011 b, 1011 d, 1011 f, 1011 h is shorter than that of the side surfaces 1011 a, 1011 c, 1011 e, 1011 g. The side surfaces 1011 a, 1011 e face each other and are parallel to each other. The side surfaces 1011 b, 1011 f face each other and are parallel to each other. The side surfaces 1011 c, 1011 a face each other and are parallel to each other. The side surfaces 1011 d, 1011 h face each other and are parallel to each other

As shown in FIG. 35, the glass panel unit 1011 includes: a pair of glass panels (first and second glass panels) 1020, 1030; a frame member 1040; a gas adsorbent 1060; and a plurality of pillars (spacers) 1070.

The pair of glass panels 1020, 1030 has the same shape. Specifically, each of the pair of glass panels 1020, 1030 has a polygonal (e.g., octagonal in this embodiment) plate shape. Examples of materials for the pair of glass panels 1020, 1030 include soda lime glass, high strain point glass, chemically tempered glass, alkali-free glass, quartz glass, Neoceram, and thermally tempered glass.

The frame member 1040 is arranged between the pair of glass panels 1020, 1030 to hermetically bond the pair of glass panels 1020, 1030 together. This allows a space, surrounded with the pair of glass panels 1020, 1030 and the frame member 1040, to be created. In addition, the space surrounded with the pair of glass panels 1020, 1030 and the frame member 1040 is a vacuum space 1050. The frame member 1040 may be made of a hot glue. in other words, the frame member 1040 is a cured hot glue. The hot glue may be a glass frit, for example. The glass frit may be a low-melting glass frit, for example. Examples of the low-melting glass frits include a bismuth-based glass frit, a lead-based glass frit, and a vanadium-based glass frit. The frame member 1040, as well as the pair of glass panels 1020, 1030, has a polygonal shape (e.g., an octagonal shape in this embodiment). The frame member 1040 is formed along the respective outer peripheries of the pair of glass panels 1020, 1030. The hot glue does not have to be a glass fit but may also be a low-melting metal or a hot-melt adhesive, for example.

The gas adsorbent 1060 is arranged in the vacuum space 1050. Specifically, the gas adsorbent 1060 has an elongate flat-plate shape and is arranged on the glass panel 1030. The gas adsorbent 1060 is used to adsorb an unnecessary gas (such as a residual gas). The unnecessary gas is a gas emitted from the hot glue forming the frame member 1040 when the hot glue is heated, for example. The gas adsorbent 1060 includes a getter. The getter is a material having the property of adsorbing molecules smaller in size than a predetermined one. The getter may be an evaporative getter, for example. The evaporative getter has the property of releasing adsorbed molecules when heated to a predetermined temperature (activation temperature) or more. This allows, even if the adsorption ability of the evaporative getter deteriorates, the evaporative getter to recover its adsorption ability by being heated to the activation temperature or more. The evaporative getter may be a zeolite or an ion-exchanged zeolite (such as a copper ion exchanged zeolite). The gas adsorbent 1060 includes a powder of this getter. Specifically, the gas adsorbent 1060 may be formed by applying a liquid including a powder of the getter (such as a dispersion liquid obtained by dispersing a powder of the getter in a liquid or a solution obtained by dissolving a powder of the getter in a liquid) and solidifying the liquid. This reduces the size of the gas adsorbent 1060, thus allowing the gas adsorbent 1060 to be arranged even when the vacuum space 1050 is narrow.

The plurality of pillars 1070 are arranged in the vacuum space 1050. The plurality of pillars 1070 is used to maintain a predetermined gap between the pair of glass panels 1020, 1030. That is to say, the plurality of pillars 1070 is used to maintain the gap distance between the pair of glass panels 1020, 1030 at a desired value. Note that the dimensions, number, spacing, and arrangement pattern of the pillars 1070 may he selected appropriately. Each of the pillars 1070 has the shape of a circular column, of which the height is approximately equal to the predetermined gap. For example, the pillars 1070 may have a diameter of 1 mm and a height of 100 μm. Optionally, the pillars 1070 may also have any other desired shape such as a prismatic or spherical shape.

The window frame 1012 surrounds the outer periphery of the glass panel unit 1011. The window frame 1012 has a polygonal shape. That is to say, the window frame 1012 is polygonal in a plan view. The outer peripheral shape of the window frame 1012 is a polygon having fewer sides than the profile of the glass panel unit 1011. The window frame 1012 has the shape of a quadrangle with four sides in a plan view. In this embodiment, the outer peripheral shape of the window frame 1012 is square in a plan view. As shown in FIG. 35, the window frame 1012 has a plurality of (e.g., four in this embodiment) corners 1012 a-1012 d.

Also, the window frame 1012 has an opening 1121 at its center. In a plan view, the opening 1121 has the same shape as the glass panel unit 1011. Thus, the opening 1121 has an octagonal shape. Accordingly, the inner periphery of the window frame 1012 has a plurality of (e.g., eight in this embodiment) inner side surfaces 1121 a-1121 h. These eight inner side surfaces 1121 a-1121 h respectively correspond to the eight sides of the opening 1121 in a plan view. In this case, the inner side surfaces 1121 a, 1121 c, 1121 e, 1121 g have an equal length. Likewise, the inner side surfaces 1121 h, 1121 d, 1121 f, 1121 h also have an equal length. Nevertheless, the length of the inner side surfaces 1121 b, 1121 d, 1121 f, 1121 h is shorter than that of the inner side surfaces 1121 a, 1121 c, 1121 e, 1121 g. The inner side surfaces 1121 a, 1121 e face each other and are parallel to each other. The inner side surfaces 1121 b, 1121 f face each other and are parallel to each other. The inner side surfaces 1121 c, 1121 g face each other and are parallel to each other. The inner side surfaces 1121 d, 1121 h face each other and are parallel to each other.

In this case, the direction in which the inner side surfaces 1121 b, 1121 f of the window frame 1012 face each other is aligned with the direction in which the corners 1012 a, 1012 c of the window frame 1012 face each other. Likewise, the direction in which the inner side surfaces 1121 d, 1121 h of the window frame 1012. face each other is aligned with the direction in which the corners 1012 b, 1012 d of the window frame 1012 face each other.

As shown in FIG. 36, the glass panel unit 1011 is fitted into the opening 1121 of the window frame 1012. At this time, the plurality of side surfaces 1011 a-1011 h of the glass panel unit 1011 respectively contact with the plurality of inner side surfaces 1121 a-1121 h of the window frame 1012. In particular, the side surfaces 1011 b, 1011 d, 1011 f, 1011 h of the glass panel unit 1011 respectively face and are in contact with the inner side surfaces 1121 b, 1121 d, 1121 f, 1121 h of the window frame 1012. This reduces the backlash of the glass panel unit 1011 with respect to the window frame 1012. In addition, the inner side surfaces 1121 b, 1121 d, 1121 f, 1121 h of the window frame 1012 respectively face the four corners 1012 a, 1012 b, 1012 c, 1012 d of the window frame 1012. Therefore, each of the side surfaces 1011 b, 1011 d, 1011 f, 1011 h of the glass panel unit 1011 constitutes a facing surface that faces an associated one of the plurality of corners 1012 a-1012 d of the outer periphery of the window frame 1012.

1.2.4. Manufacturing Method

Next, a method for manufacturing the glass panel unit 1011 for use in the glass window 1010 will be described with reference to FIGS. 37-47.

The method for manufacturing the glass panel unit 1011 includes a preparatory step (see FIGS. 37-44), a first cutting step (see FIG. 45), and a second cutting step (see FIG. 46).

The preparatory step is the step of providing the work in progress 1111 shown in FIG. 44. The work in progress 1111 includes: a pair of glass substrates (first and second glass substrates) 1200, 1300 arranged to face each other; and a frame portion 1400A arranged between the pair of glass substrates 1200, 1300 to hermetically bond the pair of glass substrates 1200, 1300 together.

The first glass substrate 1200 is a member that forms the basis of the first glass panel 1020 and is made of the same material as the first glass panel 1020. The second glass substrate 1300 is a member that forms the basis of the second glass panel 1030 and is made of the same material as the second glass panel 1030. The first and second glass substrates 1200, 1300 have the same shape and each have a polygonal shape (e.g., a rectangular shape in this embodiment). In this embodiment, the first glass substrate 1200 has dimensions that are large enough to form two first glass panels 1020, and the second glass substrate 1300 has dimensions that are large enough to form two second glass panels 1030.

As shown in FIG. 44, the frame portion 1400A includes a plurality of sidewalls (first, second, third, and fourth sidewalls) 1410A-1440A, a plurality of boundary walls (first, second, and third boundary walls) 1450A, 1460A, 1470A, and a plurality of walls (first to eighth walls) 1481A-1488A. The frame portion 1400A is made of a hot glue. The hot glue may be a glass fit, for example. The glass fit may be a low-melting glass frit, for example. Examples of the low-melting glass frits include a bismuth-based glass frit, a lead-based glass frit, and a vanadium-based glass frit.

The first, second, third, and fourth sidewalls 1410A-1440A are arranged between the respective peripheral edges of the pair of glass substrates 1200, 1300. In particular, the first, second, third, and fourth sidewalls 1410A-1440A form a rectangular frame. The first and third sidewalls 1410A, 1430A are located on both ends of the width of the pair of glass substrates 1200, 1300 and extend linearly along the length of the pair of glass substrates 1200, 1300. The second and fourth sidewalk 1420A, 1440A are located on both ends of the length of the pair of glass substrates 1200, 1300 and extend linearly along the width of the pair of glass substrates 1200, 1300.

The first boundary wall 1450A couples the first and third sidewalls 1410A, 1430A together. The first boundary wall 1450A linearly extends along the width of the pair of glass substrates 1200, 1300 and is located closer to the fourth sidewall 1440A than to the second sidewall 1420A. The second boundary wall 1460A couples the second sidewall 1420A and the first boundary wall 1450A together. The second boundary wall 1460A linearly extends along the length of the pair of glass substrates 1200, 1300 and is located closer to the first sidewall 1410A than to the third sidewall 1430A. The third boundary wall 1470A couples the third sidewall 1430A and the second boundary wall 1460A together. The third boundary wall 1470A linearly extends along the width of the pair of glass substrates 1200, 1300 and is located at the middle between the second sidewall 1420A and the first boundary wall 1450A.

The first sidewall 1410A is divided by the first boundary wall 1450A into a first part 1411A and a second part 1412A. The first part 1411A is a part, located between the second sidewall 1420A and the first boundary wall 1450A, of the first sidewall 1410A. The second part 1412A is a part, located between the first boundary wall 1450A and the fourth sidewall 1440A, of the first sidewall 1410A.

The second sidewall 1420A is divided by the second boundary wall 1460A into a first part 1421A and a second part 1422A. The first part 1421A is a part, located between the third sidewall 1430A and the second boundary wall 1460A, of the second sidewall 1420A. The second part 1422A is a part, located between the second boundary wall 1460A and the first sidewall 1410A, of the second sidewall 1420A. In addition, the first boundary wall 1450A is divided by the second boundary wall 1460A into a first part 1451A and a second part 1452A. The first part 1451A is a part, located between the third sidewall 1430A and the second boundary wall 1460A, of the first boundary wall 1450A. The second part 1452A is a part, located between the second boundary wall 1460A and the first sidewall 1410A, of the first boundary wall 1450A.

The second boundary wall 1460A is divided by the third boundary wall 1470A into a first part 1461A and a second part 1462A. The first part 1461A is a part, located between the second sidewall 1420A and the third boundary wall 1470A, of the second boundary wall 1460A. The second part 1462A is a part, located between the third boundary wall 1470A and the first boundary wall 1450A, of the second boundary wall 1460A.

The third sidewall 1430A is divided by the first boundary wall 1450A and the third boundary wall 1470A into a first part 1431A, a second part 1432A, and a third part 1433A. The first part 1431A is a part, located between the second sidewall 1420A and the third boundary wall 1470A, of the third sidewall 1430A. The second part 1432A is a part, located between the third boundary wall 1470A and the first boundary wall 1450A, of the third sidewall 1430A. The third part 1433A is a part, located between the first boundary wall 1450A and the fourth sidewall 1440A, of the third sidewall 1430A.

The first to fourth walls 1481A-1484A are located in the space surrounded with the first part 1421A of the second sidewall 1420A, the first part 1431A of the third sidewall 1430A, the third boundary wall 1470A, and the first part 1461A of the second boundary wall 1460A. The first wall 1481A is located at the corner between the first part 1421A of the second sidewall 1420A and the first part 1431A of the third sidewall 1430A and extends linearly so as to cross the first part 1421A of the second sidewall 1420A and the first part 1431A of the third sidewall 1430A. The second wall 1482A is located at the corner between the first part 1431A of the third sidewall 1430A and the third boundary wall 1470A and extends linearly so as to cross the first part 1431A of the third sidewall 1430A and the third boundary wall 1470A. The third wall 1483A is located at the corner between the third boundary wall 1470A and the first part 1461A of the second boundary wall 1460A and extends linearly so as to cross the third boundary wall 1470A and the first part 1461A of the second boundary wall 1460A. The fourth wall 1484A is located at the corner between the first part 1461A of the second boundary wall 1460A and the first part 1421A of the second sidewall 1420A and extends linearly so as to cross the first part 1461A of the second boundary wall 1460A and the first part 1421A of the second sidewall 1420A.

The fifth to eighth walls 1485A-1488A are located in the space surrounded with the third boundary wall 1470A, the second part 1432A of the third sidewall 1430A, the first part 1451A of the first boundary wall 1450A and the second part 1462A of the second boundary wall 1460A. The fifth wall 1485A is located at the corner between the third boundary wall 1470A and the second part 1432A of the third sidewall 1430A and extends linearly so as to cross the third boundary wall 1470A and the second part 1432A of the third sidewall 1430A. The sixth wall 1486A is located at the corner between the second part 1432A of the third sidewall 1430A and the first part 1451A of the first boundary wall 1450A and extends linearly so as to cross the second part 1432A of the third sidewall 1430A and the first part 1451A of the first boundary wall 1450A. The seventh wall 1487A is located at the corner between the first part 1451A of the first boundary wall 1450A and the second part 1462A of the second boundary wall 1460A and extends linearly so as to cross the first part 1451A of the first boundary wall 1450A and the second part 1462A of the second boundary wall 1460A. The eighth wall 1488A is located at the corner between the second part 1462A of the second boundary wall 1460A and the third boundary wall 1470A and extends linearly so as to cross the second part 1462A of the second boundary wall 1460A and the third boundary wall 1470A.

In the frame portion 1400A, the first to fourth walls 1481A-1484A, along with the respective middle portions of the first part 1421A of the second sidewall 1420A, the first part 1431A of the third sidewall 1430A, the third boundary wall 1470A, and the first part 1461A of the second boundary wall 1460A, form the frame member 1040 (1040 a). Meanwhile, the first part 1421A of the second sidewall 1420A, the first part 1431A of the third sidewall 1430A, the third boundary wall 1470A, and the first part 1461A of the second boundary wall 1460A in their entirety form an auxiliary frame member 1041 (1041 a) having the shape of a polygon circumscribed about the frame member 1040 a. The auxiliary frame member 1041 a has the shape of a polygon having fewer sides than the frame member 1040 a. In this embodiment, the auxiliary frame member 1041 a has a square shape in a plan view. Also, the fifth to eighth walls 1485A-1488A, along with the respective middle portions of the third boundary wall 1470A, the second part 1432A of the third sidewall 1430A, the first part 1451A of the first boundary wall 1450A, and the second part 1462A of the second boundary wall 1460A, form the frame member 1040 (1040 b). Meanwhile, the third boundary wall 1470A, the second part 1432A of the third sidewall 1430A, the first part 1451A of the first boundary wall 1450A, and the second part 1462A of the second boundary wall 1460A in their entirety form an auxiliary frame member 1041 (1041 b) having the shape of a polygon circumscribed about the frame member 1040 b. The auxiliary frame member 1041 b has the shape of a polygon having fewer sides than the frame member 1040 b. In this embodiment, the auxiliary frame member 1041 b has a square shape in a plan view. As can be seen, the frame portion 1400A includes a plurality of frame members 1040 (1040 a, 1040 b) and a plurality of auxiliary frame members 1041 (1041 a, 1041 b).

In addition, the work in progress 1111 further includes, in the space surrounded with each of the frame members 1040 (1040 a, 1040 b), the gas adsorbent 1060 and the plurality of pillars 1070.

Besides, the work in progress 1111 further includes the evacuation port 1700. The evacuation port 1700 is located in a region, surrounded with the first boundary wall 1450A, the third part 1433A of the third sidewall 1430A, the fourth sidewall 1440A, and the second part 1412A of the first sidewall 1410A, on the first glass substrate 1200.

The preparatory step is the step of providing the work in progress 1111 described above, and include an assembling step (see FIGS. 37-42), a first melting step (see FIG. 43), an evacuation step (see FIG. 43), and a second melting step (see FIG. 43).

The assembling step is the step of providing the assembly 1110 shown in FIG. 42. The assembly 1110 includes the pair of glass substrates 1200, 1300, a sealant 1400, air passages 1611, 1612, 1621, 1622, 1630, and the evacuation port 1700.

The sealant 1400 is a material for making the frame portion 1400A. As shown in FIG. 40, the sealant 1400 includes a plurality of outer portions (first, second, third, and fourth outer portions) 1410-1440, a plurality of inner portions (first, second, and third inner portions) 1450, 1460, 1470, and a plurality of wall portions (first to eighth wall portions) 1481-1488.

The first, second, third, and fourth outer portions 1410-1440 are portions to form the first, second, third, and fourth sidewalls 1410A-1440A, respectively. In particular, the first outer portion 1410 includes parts 1411, 1412 respectively corresponding to the first and second parts 1411A, 1412A of the first sidewall 1410A. The second outer portion 1420 includes parts 1421, 1422 respectively corresponding to the first and second parts 1421A, 1422A of the second sidewall 1420A. The third outer portion 1430 includes parts 1431, 1432, 1433 respectively corresponding to the first, second, and third parts 1431A, 1432A, 1433A of the third sidewall 1430A. Also, the first inner portion 1450 includes parts 1451, 1452 respectively corresponding to the first and second parts 1451A, 1452A of the first boundary wall 1450A. The second inner portion 1460 includes parts 1461, 1462 respectively corresponding to the first and second parts 1461A, 1462A of the second boundary wall 1460A.

The first, second, third, and fourth outer portions 1410-1440 of the sealant 1400 together form the frame-shaped first sealant 1401 to be arranged between the pair of glass substrates 1200, 1300. Thus, the work in progress 1111 has an internal space 1500 surrounded with the pair of glass substrates 1200, 1300 and the first sealant 1401. Also, the first to fourth wall portions 1481-1484 form, along with the respective middle portions of the part 1421 of the second outer portion 1420, the part 1431 of the third outer portion 1430, the third inner portion 1470, and the part 1461 of the second inner portion 1460, the second sealant 1402 a to form part of the frame member 1040 a. Likewise, the fifth to eighth wall portions 1485-1488 form, along with the respective middle portions of the third inner portion 1470, the part 1432 of the third outer portion 1430, the part 1451 of the first inner portion 1450, and the part 1462 of the second inner portion 1460, the second sealant 1402 b to form part of the frame member 1040 b. The second sealants 1402 a, 1402 b partition the internal space 1500 into a first space 1510 surrounded with the pair of glass substrates 1200, 1300 and the second sealants 1402 a, 1402 b and second spaces 1520. In this case, the second spaces 1520 include a space 1521 and a space 1522. The space 1521 is a space surrounded with the pair of glass substrates 1200, 1300, the first inner portion 1450, the part 1433 of the third outer portion 1430, the fourth outer portion 1440, and the part 1412 of the first outer portion 1410. The space 1522 is a space surrounded with the pair of glass substrates 1200, 1300, the part 1422 of the second outer portion 1420, the second inner portion 1460, the part 1452 of the first inner portion 1450, and the part 1412 of the first outer portion 1410.

As can be seen, the sealant 1400 includes the first sealant 1401 and the second sealants 1402 a, 1402 b. The first sealant 1401 is a frame-shaped member and is arranged between the pair of glass substrates 1200, 1300. The second sealants 1402 a, 1402 b partition the internal space 1500 surrounded with the pair of glass substrates 1200, 1300 and the first sealant 1401 into the first space 1510 and the second spaces 1520.

The air passages 1611, 1612, 1621, 1622, 1630 are formed through the sealant 1400. These air passages 1611, 1612, 1621, 1622, 1630 are provided to connect the first space 1510 and the second spaces 1520 each other either directly or indirectly. The air passage 1611 is provided for the part 1451 of the first inner portion 1450 to connect together the first space 1510 defined by the second sealant 1402 b and the space 1521. The air passage 1612 is provided for the part 1452 of the first inner portion 1450 to connect the spaces 1522, 1521 together. The air passage 1621 is provided for the part 1461 of the second inner portion 1460 to connect together the first space 1510 defined by the second sealant 1402 b and the space 1522. The air passage 1622 is provided for the part 1462 of the second inner portion 1460 to connect the first space 1510 defined by the second sealant 1402 b and the space 1522. The air passage 1630 is provided for the third inner portion 1470 to connect the respective first spaces 1510 defined by the second sealants 1402 a, 1402 b together.

The evacuation port 1700 is cut through the first glass substrate 1200. As to the assembly 1110, the evacuation port 1700 is cut through the first glass substrate 1200 to connect the second space 1520 (space 1521) and the external environment together.

The assembly 1110 includes the gas adsorbent 1060 and the plurality of pillars 1070 in each of the first spaces 1510.

The assembling step is the step of forming the first glass substrate 1200, the second glass substrate 1300, the sealant 1400, the internal space 1500, the air passages 1611, 1612, 1621. 1622, 1630, the evacuation port 1700, the plurality of gas adsorbents 1060, and the plurality of pillars 1070 to obtain the assembly 1110. The preparatory step includes first to sixth steps. Note that the order in which the second to fifth steps are performed may be changed as appropriate.

The first step is the step of forming the first glass substrate 1200 and the second glass substrate 1300 (substrate forming step). For example, the first step includes making the first glass substrate 1200 and the second glass substrate 1300. If necessary, the first step further includes cleaning the first glass substrate 1200 and the second glass substrate 1300.

The second step is the step of forming the evacuation port 1700. The second step includes cutting the evacuation port 1700 through the first glass substrate 1200 as shown in FIG. 37. If necessary, the second step further includes cleaning the first glass substrate 1200.

The third step is the step of forming the spacers 1070 (spacer forming step). The third step includes forming a plurality of spacers 1070 in advance and placing the plurality of spacers 1070 at predetermined positions on the first glass substrate 1200 using a chip mounter 1800, for example, as shown in FIG. 38. Alternatively, the plurality of spacers 1070 may also be formed by a combination of photolithography and etching techniques. In that case, the plurality of spacers 1070 may be made of a photocurable material, for example. Still alternatively, the plurality of spacers 1070 may also be formed by a known thin film deposition technique.

The fourth step is the step of forming the gas adsorbents 1060 (gas adsorbent forming step). The fourth step includes forming the gas adsorbents 1060 by applying a solution in which a powder of a getter is dispersed onto predetermined positions on the first glass substrate 1200 using a dispenser 1810, for example, and drying the solution as shown in FIG. 39.

The fifth step is the step of arranging the sealants 1400 including the first sealant 1401 and the second sealants 1402 a, 1402 b (sealant arranging step). In the third step, the sealant 1400 is applied onto the first glass substrate 1200 using the dispenser 1820, for example, and then allowed to dry. Optionally, the fifth step may include pre-baking the sealants 1400 while drying the sealant 1400. For example, the first glass substrate 1200 onto which the sealants 1400 are applied may be heated at 480° C. for 20 minutes. In this case, the second glass substrate 1300 may also be heated along with the first glass substrate 1200. That is to say, the first glass substrate 1200 may be heated under the same condition (at 480° C. for 20 minutes) as the second glass substrate 1300. This reduces the difference in the degree of warpage between the first glass substrate 1200 and the second glass substrate 1300.

The first glass substrate 1200 such as the one shown in FIG. 40 is obtained by performing the first to fifth steps described above. On this first glass substrate 1200, the sealants 1400 (including the first sealant 1401 and the second sealants 1402 a, 1402 b), the air passages 1611, 1612, 1621, 1622, 1630, the evacuation port 1700, the plurality of gas adsorbents 1060, and the plurality of pillars 1070 have been formed.

The sixth step is the step of arranging the first glass substrate 1200 and the second glass substrate 1300 (arrangement step). The sixth step includes arranging the first glass substrate 1200 and the second glass substrate 1300 such that the first glass substrate 1200 and the second glass substrate 1300 are parallel to each other and face each other as shown in FIG. 41.

The assembly 1110 shown in FIG. 42 is obtained by performing such an assembling step. After the assembling step has been performed, the first melting step, the evacuation step, and the second melting step are performed as shown in FIG. 43.

The first melting step is the step of melting the first sealant 1401 once to hermetically bond the pair of glass substrates 1200, 1300 together with the first sealant 1401. Specifically, the first glass substrate 1200 and the second glass substrate 1300 are loaded into a melting furnace and heated at a first melting temperature Tm1 for a predetermined amount of time (first melting time) tm1 (see FIG. 43). The first melting temperature Tm1 and the first melting time tm1 are set such that the glass substrates 1200, 1300 are hermetically bonded together with the first sealant 1401 but that the air passages 1611, 1621, 1622 are not closed with the second sealants 1402 a, 1402 b. That is to say, the lower limit of the first melting temperature Tm1 is the softening point of the sealant 1400 but the upper limit of the first melting temperature Tm1 is set such that the air passages 1611, 1621, 1622 are not closed with the second sealants 1402 a, 1402 b. For example, if the softening point is 434° C., the first melting temperature Tm1 is set at 440° C. The first melting time tm1 may be 10 minutes, for example.

The evacuation step is the step of evacuating the first space 1510 through the air passages 1611, 1612, 1621, 1622, 1630, the second spaces 1520, and the evacuation port 1700 and thereby turning the first space 1510 into a vacuum space 1050. The evacuation may be carried out using a vacuum pump, for example. The vacuum pump may be connected to the assembly 1110 via an evacuation pipe 1830 and a sealing head 1840 as shown in FIG. 42. The evacuation pipe 1830 may be bonded to the first glass substrate 1200 such that the inside of the evacuation pipe 1830 and the evacuation port 1700 communicate with each other, for example. Then, the sealing head 1840 is attached to the evacuation pipe 1830, thereby connecting a suction port of the vacuum pump to the evacuation port 1700. The first melting step, the evacuation step, and the second melting step are performed with the assembly 1110 kept loaded in the melting furnace. Therefore, the evacuation pipe 1830 is bonded to the first glass substrate 1200 at least before the first melting step.

The evacuation step includes evacuating the first space 1510 at an evacuation temperature Te for a predetermined amount of time (evacuation time) te via the air passages 1611, 1612, 1621, 1622, 1630 and the second spaces 1520 (see FIG. 43). The evacuation temperature Te is set at a temperature higher than the activation temperature (e.g., 350° C.) of the getter of the gas adsorbent 1060 but lower than the softening point (e.g., 434° C.) of the sealant 1400. The evacuation temperature Te may be 390° C., for example. This prevents the sealant 1400 from being deformed. In addition, this causes the getter of the gas adsorbent 1060 to be activated and also causes the molecules (gas) adsorbed onto the getter to be released from the getter. Then, the molecules (i.e., the gas) released from the getter is exhausted through the first space 1510, the air passages 1611, 1612, 1621, 1622, 1630, the second spaces 1520, and the evacuation port 1700. Thus, this evacuation step allows the gas adsorbent 1060 to recover its adsorption ability. The evacuation time te is set so as to create a vacuum space 1050 with a predetermined degree of vacuum (e.g., a degree of vacuum of 0.1 Pa or less). The evacuation time te may be set at 120 minutes, for example.

The second melting step is the step of closing at least the air passages 1611, 1621, 1622, 1630 by deforming the second sealants 1402 a, 1402 b to form the frame members 1040 a, 1040 b and thereby obtain the work in progress 1111. That is to say, the second melting step includes closing the air passages 1611, 1621, 1622, 1630 by deforming the second sealants 1402 a, 1402 b to form the frame members 1040 a, 1040 b surrounding the vacuum space 1050 (see FIG. 44). Melting the second sealants 1402 a, 1402 b once at a predetermined temperature (second melting temperature) Tm2 equal to or higher than the softening point of the sealants 1400 causes the second sealants 1402 a, 1402 b to be deformed to form the frame members 1040 a, 1040 b. Specifically, the first glass substrate 1200 and the second glass substrate 1300 are heated in the melting furnace at a second melting temperature Tm2 for a predetermined amount of time (second melting time) tm2 (see FIG. 44). The second melting temperature Tm2 and the second melting time tm2 are set such that the second sealants 1402 a, 1402 b are softened to close the air passages 1611, 1621, 1622, 1630. The lower limit of the second melting temperature Tm2 is the softening point (434° C.) of the sealants 1400. However, unlike the first melting step, the second melting step is performed to deform the second sealants 1402 a, 1402 b. Thus, the second melting temperature Tm2 is set at a temperature higher than the first melting temperature (440° C.) Tm1. The second melting temperature Tm2 may be set at 460° C., for example. Also, the second melting time tm2 may be 30 minutes, for example. Stated otherwise, the first melting temperature Tm1 is set at a temperature lower than the second melting temperature Tm2. This reduces the chances of, when the first glass substrate 1200 and the second glass substrate 1300 are bonded together with the first sealant 1401, the second sealants 1402 a, 1402 b being deformed to close the air passages 1611, 1621, 1622, 1630. In addition, in the second melting step, the first space 1510 continues to be evacuated, as in the evacuation step, via the air passages 1611, 1612, 1621, 1622, 1630, the second space 1520, and the evacuation port 1700. That is to say, in the second melting step, the first space 1510 is evacuated at the second melting temperature Tm2 via the air passages 1611, 1612, 1621, 1622, 1630, the second spaces 1520, and the evacuation port 1700. In the meantime, the air passages 1611, 1612, 1621, 1622, 1630 are closed by deforming the twelfth sealants 1402 a, 1402 b. This further reduces the chances of the degree of vacuum of the vacuum space 1050 decreasing during the second melting step. Nevertheless, in the second melting step, the first space 1510 does not have to be evacuated via the air passages 1611, 1612, 1621, 1622, 1630, the second spaces 1520, and the evacuation port 1700.

The work in progress 1111 shown in FIG. 44 is obtained by performing the preparatory step described above. After the preparatory step has been performed, the first cutting step (see FIG. 45) and the second cutting step (see FIG. 46) are performed. Note that in FIGS. 45 and 46, the frame member 1040 and the auxiliary frame member 1041 are indicated by two different types of shades just for the purpose of making the description more easily understandable.

The first cutting step is the step of cutting the work in progress 1111 along a polygon circumscribed about the frame member 1040 to obtain predetermined parts 1112 each including the frame member 1040. The work in progress 1111 includes the auxiliary frame member 1041 in the shape of a polygon circumscribed about the frame members 1040 as shown in FIG. 45. The first cutting step includes cutting the work in progress 1111 along the outer periphery of the auxiliary frame member 1041. In this manner, the predetermined parts 1112 are obtained. In this embodiment, the work in progress 1111 has two frame members 1040, and therefore, two predetermined parts 1112 are obtained as a result of the first cutting step. Specifically, first, the work in progress 1111 is cut along a cutting line 1910 aligned with the first boundary wall 1450A to remove an unnecessary part 1113 as shown in FIG. 45. Thereafter, the work in progress 1111, from which the unnecessary part 1113 has been removed, is cut along a cutting line 1920 aligned with the second boundary wall 1460A to remove another unnecessary part 1114. In this manner, the two predetermined parts 1112 that are still combined together are obtained. Subsequently, the two predetermined parts 112 combined together are cut off along a cutting line 1930 aligned with the third boundary wall 1470A to separate the two predetermined parts 1112 from each other. This allows the work in progress 1111 to be cut off along the outer periphery of the auxiliary frame members 1041 to obtain the two predetermined parts 1112. Since the auxiliary frame members 1041 each have a square shape, the predetermined parts 1112 also have a square shape.

The second cutting step is the step of cutting each of the predetermined parts 1112 along the outer periphery of the frame member 1040 to obtain a glass panel unit 1011 including the frame member 1040 and respective parts, corresponding to the frame member 1040, of the pair of glass substrates 1200, 1300 (i.e., the pair of glass panels 1020, 1030). Specifically, as shown in FIG. 46, each of the predetermined parts 1112 is cut off along cutting lines 1940 aligned with the walls (1481A-1484A; 1485A-1488A) to remove unnecessary parts 1115. In this embodiment, portions corresponding to the four corners of the predetermined part 1112 are removed as unnecessary parts 1115 from the predetermined part 1112. In this manner, the glass panel unit 1011 shown in FIG. 47 is obtained.

1.2.5. Brief Summary

As can be seen from the foregoing description, the problem to overcome by the second embodiment is to provide a glass window and a method for manufacturing a glass panel unit, both of which are able to reduce the unbeneficial effect of glass warpage due to heat. A glass window (1010) according to the second embodiment includes a polygonal glass panel unit (1011) and a polygonal window frame (1012). The glass panel unit (1011) includes: a pair of glass panels (1020, 1030) arranged to face each other; and a frame member (1040) arranged between the pair of glass panels (1020, 1030) to hermetically bond the pair of glass panels (1020, 1030) together. The window frame (1012) surrounds an outer periphery of the glass panel unit (1011). The glass panel unit (1011) has a plurality of side surfaces (1011 a-1011 h). The plurality of side surfaces (1011 a-1011 h) includes at least one facing surface (1011 b, 1011 d, 1011 f, 1011 h) that faces an associated one of a plurality of corners (1012 a-1012 d) of the outer periphery of the window frame (1012; 1012A).

2. Variations

Note that embodiments described above are only examples of the present disclosure and should not be construed as limiting. Rather, those embodiments may be readily modified in various manners depending on a design choice or any other factor without departing from the scope of the present disclosure. Next, variations of the embodiments described above will be enumerated one after another.

2.1. Variations of First Embodiment

2.1.1. First Variation

FIG. 24 illustrates a work in progress 110A of glass panel units according to a first variation. As shown in FIG. 24, the work in progress 110A of glass panel units according to this first variation has the same configuration as the work in progress 110 except the boundary walls 42A, which are different from the boundary walls 42 of the work in progress 110. The boundary walls 42A hermetically separate the internal space 500, surrounded with the pair of glass substrates 200, 300 and the peripheral wall 41, into a plurality of (e.g., seven in the example illustrated in FIG. 24) evacuation spaces 511, a buffer space 512, and a ventilation space 520. In this first variation, the boundary walls 42A hermetically separate the plurality of evacuation spaces 511, the buffer space 512, and the ventilation space 520 on an individual basis. The plurality of evacuation spaces 511 for use as the glass panel unit each have a quadrangular shape in a plan view but do not have the same dimensions or shapes. In this work in progress 110A, the evacuation spaces 511 and the buffer space 512 have a lower internal pressure than the ventilation space 520 (e.g., may be in a vacuum condition). Also, a predetermined part, excluding the buffer space 512 and the ventilation space 520 but including the evacuation spaces 511, of the work in progress 110A forms glass panel units. In this work in progress 110A, the plurality of pillars 70 are placed over the entire internal space 500 (i.e., including the seven evacuation spaces 511, the buffer space 512, and the ventilation space 520). That is to say, the plurality of pillars 70 are placed over the evacuation spaces 511, the buffer space 512, and the ventilation space 520. Meanwhile, the gas adsorbent 60 is arranged only in each of the evacuation spaces 511. That is to say, the gas adsorbents 60 are arranged in the evacuation spaces 511, not in the buffer space 512 or the ventilation space 520.

The work in progress 110A may be obtained from the glass panel unit assembly 100A shown in FIG. 25. Just like the assembly 100, the assembly 100A also includes: a pair of glass substrates 200, 300; a peripheral wall 410; a plurality of partitions 420; a plurality of air passages 600; an evacuation port 700; gas adsorbents 60; and pillars 70.

The plurality of partitions 420 is provided to form boundary walls 42A. Thus, the plurality of partitions 420 partitions the internal space 500 into a plurality of (e.g., seven in the example illustrated in FIG. 25) evacuation spaces 511, a buffer space 512, and a ventilation space 520. As shown in FIG. 25, the plurality of partitions 420 includes a plurality of (e.g., eight in the example illustrated in FIG. 25) first partitions 421 and a plurality of (e.g., eight in the example illustrated in FIG. 25) second partitions 422. Note that the peripheral wall 410 and the partitions 420 may be formed by the same techniques as the ones adopted in the embodiments described above. For example, to form the peripheral wall 410, as in the peripheral wall forming step of the embodiment described above, the dispenser 810 may be moved along the peripheral edges of the second glass substrate 300 and along the path T10 shown in FIG. 26 while discharging the material M10 through the nozzle 811. In the same way, to form the partitions 420, as in the partition forming step of the embodiment described above, the dispenser 820 may be moved along the sides of the quadrangle and along the paths T21 and T22 shown in FIG. 26 while discharging the material M20 through the nozzle 821. At this time, a swollen portion 425 may be provided at an end 423 of each partition 420 as in the embodiments described above.

The plurality of air passages 600 is used to evacuate the first space (including the evacuation spaces 511 and the buffer space 512) through the evacuation port 700. Through the plurality of air passages 600. the evacuation spaces 511 and the buffer space 512 are connected (either directly or indirectly) to the ventilation space 520. In FIG. 25, the peripheral wall 410 and the partitions 420 are arranged out of contact with each other. In addition, each of the gaps between the peripheral wall 410 and the partitions 420 constitutes one of the air passages 600. Each of these air passages 600 is closed by melting and deforming an associated one of the partitions 420 once. This allows at least the evacuation spaces 511 to be (hermetically) separated from each other and also allows the evacuation spaces 511 and the buffer space 512 to be (hermetically) separated from the ventilation space 520.

The plurality of air passages 600 includes a plurality of (first) particular air passages 610 which are arranged side by side in the second direction perpendicular to the first direction in which the pair of glass substrates 200, 300 face each other. The plurality of first particular air passages 610 constitute (first) ventilation paths P10 running through the internal space 500 in the second direction (i.e., the upward/downward direction in FIG. 25). The plurality of air passages 600 further includes (second) particular air passages 620 which are arranged side by side in the third direction perpendicular to the first direction and intersecting with the second direction. The plurality of second particular air passages 620 constitute (second) ventilation paths P20 running through the internal space 500 in the third direction (i.e., the rightward/leftward direction in FIG. 25). Note that in FIG. 25, the ventilation paths P10, P20 are shaded just for the purpose of making the description more easily understandable.

As can be seen, the assembly 100A includes the plurality of first ventilation paths P10 running in the second direction and the plurality of second ventilation paths P20 running in the third direction as shown in FIG. 25. This allows the assembly 100A to pass not only hot air blowing in the second direction but also hot air blowing in the third direction as well. This causes the heat to be conducted more efficiently through the partitions 420 in the internal space 500 of the assembly 100A, thus facilitating heating the partitions 420. This allows unnecessary components such as a binder included in the material (second sealant) for the partitions 420 which often emits a gas to be removed sufficiently through the first melting step.

2.1.2. Second Variation

FIG. 27 illustrates a glass panel unit assembly 100B according to a second variation. The assembly 100B, as well as the assembly 100A, may also be used to form the work in progress 110A of glass panel units according to the first variation shown in FIG. 24.

Just like the assembly 100A, the assembly 100B also includes: a pair of glass substrates 200, 300; a peripheral wall 410; a plurality of partitions 420; a plurality of air passages 600; an evacuation port 700; gas adsorbents 60; and pillars 70. Note that in FIG. 27, illustration of the gas adsorbents 60 and the pillars 70 is omitted just for the sake of simplicity.

The plurality of partitions 420 is provided to form boundary walls 42A. Thus, the plurality of partitions 420 partitions the internal space 500 into a plurality of (e.g., seven in the example illustrated in FIG. 27) evacuation spaces 511, a buffer space 512, and a ventilation space 520. As shown in FIG. 27, the plurality of partitions 420 includes a plurality of (e.g., four in the example illustrated in FIG. 27) first partitions 421 and a plurality of (e.g., four in the example illustrated in FIG. 27) second partitions 422. Note that the peripheral wall 410 and the partitions 420 may be formed by the same techniques as the ones adopted in the embodiments described above. For example, to form the peripheral wall 410, as in the peripheral wall forming step of the embodiment described above, the dispenser 810 may be moved along the peripheral edges of the second glass substrate 300 and along the path T10 shown in FIG. 28 while discharging the material M10 through the nozzle 811. In the same way, to form the partitions 420, as in the partition forming step of the embodiment described above, the dispenser 820 may be moved along the sides of the quadrangle and along the paths T21 and T22 shown in FIG. 28 while discharging the material M20 through the nozzle 821. At this time, a swollen portion 425 may be provided at an end 423 of each partition 420 as in the embodiments described above.

The plurality of air passages 600 is used to evacuate the first space (including the evacuation spaces 511 and the buffer space 512) through the evacuation port 700. Through the plurality of air passages 600, the evacuation spaces 511 and the buffer space 512 are connected (either directly or indirectly) to the ventilation space 520. In FIG. 27, the peripheral wall 410 and the partitions 420 are arranged out of contact with each other. In addition, each of the gaps between the peripheral wall 410 and the partitions 420 constitutes one of the air passages 600. Each of these air passages 600 is closed by melting and deforming an associated one of the partitions 420 once. This allows at least the evacuation spaces 511 to be (hermetically) separated from each other and also allows the evacuation spaces 511 and the buffer space 512 to be (hermetically) separated from the ventilation space 520.

The plurality of air passages 600 includes a plurality of particular air passages 610 which are arranged side by side in the second direction perpendicular to the first direction in which the pair of glass substrates 200, 300 face each other. The plurality of particular air passages 610 constitute ventilation paths P10 running through the internal space 500 in the second direction (i.e., the upward/downward direction in FIG. 27). Note that in FIG. 27, the ventilation paths P10 are shaded just for the purpose of making the description more easily understandable.

As can be seen, the assembly 100B includes the plurality of ventilation paths P10 running in the second direction as shown in FIG. 27. This allows unnecessary components such as a binder included in the material (second sealant) for the partitions 420 which often emits a gas to be removed through the first melting step as sufficiently as in the embodiments described above. In addition, even though the assembly 100B includes a smaller number of partitions 420 than the assembly 100A, the same work in progress 110A (see FIG. 24) as that of the assembly 100A may be obtained from the assembly 100B.

2.1.3. Third Variation

FIG. 29 illustrates a glass panel unit assembly 1000 according to a third variation. The assembly 1000, as well as the assemblies 100A, 100B, may also be used to form the work in progress 110A of glass panel units according to the first variation shown in FIG. 24.

Just like the assemblies 100A, 100B, the assembly 1000 also includes: a pair of glass substrates 200, 300; a peripheral wall 410; a plurality of partitions 420; a plurality of air passages 600; an evacuation port 700; gas adsorbents 60; and pillars 70. Note that in FIG. 29, illustration of the gas adsorbents 60 and the pillars 70 is omitted just for the sake of simplicity.

The plurality of partitions 420 is provided to form boundary walls 42A. Thus, the plurality of partitions 420 partitions the internal space 500 into a plurality of (e.g., seven in the example illustrated in FIG. 29) evacuation spaces 511, a buffer space 512, and a ventilation space 520. As shown in FIG. 29, the plurality of partitions 420 includes a plurality of (e.g., five in the example illustrated in FIG. 29) first partitions 421 and a plurality of (e.g., three in the example illustrated in FIG. 29) second partitions 422. Note that the peripheral wall 410 and the partitions 420 may be formed by the same techniques as the ones adopted in the embodiments described above. For example, to form the peripheral wall 410, as in the peripheral wall forming step of the embodiments described above, the dispenser 810 may be moved along the peripheral edges of the second glass substrate 300 and along the path T10 shown in FIG. 28 while discharging the material M10 through the nozzle 811. In the same way, to form the partitions 420, as in the partition forming step of the embodiment described above, the dispenser 820 may be moved along the sides of the quadrangle and along the paths T21 and T22 shown in FIG. 30 while discharging the material M20 through the nozzle 821. At this time, a swollen portion 425 may be provided at an end 423 of each partition 420 as in the embodiments described above.

The plurality of air passages 600 is used to evacuate the first space (including the evacuation spaces 511 and the buffer space 512) through the evacuation port 700. Through the plurality of air passages 600, the evacuation spaces 511 and the buffer space 512 are connected (either directly or indirectly) to the ventilation space 520. In FIG. 29, the peripheral wall 410 and the partitions 420 are arranged out of contact with each other. In addition, each of the gaps between the peripheral wall 410 and the partitions 420 constitutes one of the air passages 600. Each of these air passages 600 is closed by melting and deforming an associated one of the partitions 420 once. This allows at least the evacuation spaces 511 to be (hermetically) separated from each other and also allows the evacuation spaces 511 and the buffer space 512 to be (hermetically) separated from the ventilation space 520.

The plurality of air passages 600 includes a plurality of particular air passages 610 which are arranged side by side in the second direction perpendicular to the first direction in which the pair of glass substrates 200, 300 face each other. The plurality of particular air passages 610 constitute a ventilation path P10 running through the internal space 500 in the second direction (i.e., the upward/downward direction in FIG. 29). Note that in FIG. 29, the ventilation path P10 is shaded just for the purpose of making the description more easily understandable.

As can be seen, the assembly 100C includes the ventilation path P10 running in the second direction as shown in FIG. 29. This allows unnecessary components such as a binder included in the material (second sealant) for the partitions 420 which often emits a gas to be removed through the first melting step as sufficiently as in the embodiments described above. In addition, even though the assembly 1000 includes a smaller number of partitions 420 than the assembly 100A, the same work in progress 110A (see FIG. 24) as that of the assembly 100A may be obtained from the assembly 1000.

2.1.4. Fourth Variation

A glass panel unit assembly according to a fourth variation includes partitions 420 (in particular, the second partitions 422) with a different shape from their counterparts of the embodiments described above as shown in FIG. 31. FIG. 31 illustrates a state where the plurality of partitions 420 includes a first partition 421 and a second partition 422, of which the lengths are defined in two different directions. In this variation, one end 423 of the second partition 422 faces a side portion 424 of the first partition 421 with a predetermined gap left between them. The air passage 600 is a space between the end 423 of the second partition 422 and the side portion 424 of the first partition 421. As shown in FIG. 31, the second partition 422 has, at the end 423 thereof, a swollen portion 425 protruding toward both ends along the width of the second partition 422 (i.e., in the upward/downward direction shown in FIG. 31), More specifically, the swollen portion 425 has portions obliquely protruding from the end 423 toward both ends along the width of the second partition 422. That is to say, the swollen portion 425 shown in FIG. 31 has a so-called “heart shape.”

This swollen portion 425 also makes the angle formed by the corner portion C10 closer to the angle of intersection between the first partition 421 and the second partition 422 (e.g., 90 degrees in this embodiment) as shown in FIG. 13. This curbs a decrease in the strength at a connecting portion between regions S10, S20 defined by the partitions 421, 422 and a decline in appearance. Optionally, the swollen portion 425 may be provided for each of both ends 423 of the partition 421. This curbs a decrease in the strength at each of the connecting portions between the boundary walls 42 and the peripheral wall 41 and a decline in appearance. In addition, the swollen portion 425 according to this variation, as well as the swollen portion 425 of the embodiments described above, may protrude toward the evacuation space 511 at least along the width of the second partition 422.

The swollen portion 425 shown in FIG. 31 may be formed by moving the dispenser 820 along the path T23 while discharging the material M20 through the nozzle 821. The path T23 includes sections for forming the swollen portion 425 (as indicated by the arrows A21, A23, A25, A26). That is to say, moving the dispenser 820 along the path T23 as indicated by the arrows A21-A27 allows a partition 422 having the swollen portion 425 at the end 423 to be formed. Note that the rate of applying the material M20 through the dispenser 820 may be constant.

As can be seen, the shape of the swollen portion 425 is not particularly limited as long as the swollen portion 425 protrudes toward both ends along the width of the second partition 422. Optionally, the swollen portion 425 may be provided as needed for any partition 420, no matter whether it is the first partition 421 or the second partition 422. For example, the end 423 of a partition 420 may face the peripheral wall 410 with a predetermined gap left between them and an air passage 600 may be a space between the end 423 of the partition 420 and the peripheral wall 410. In that case, the partition 420 may include, at the end 423 thereof, the swollen portion 425 protruding toward the evacuation space 511 at least along the width of the partition 420. In particular, the partition 420 may include, at the end 423 thereof, a swollen portion 425 protruding toward both ends along the width of the partition 420.

2.1.5. Fifth Variation

A glass panel unit assembly according to a fifth variation includes partitions 420 (in particular, a first partition 421) having a different shape from the counterparts of the embodiments described above, as shown in FIG. 32. FIG. 32 illustrates a state where the plurality of partitions 420 includes a first partition 421 and a second partition 422, of which the lengths are defined in two different directions. In addition, the second partition 422 is supposed to be located between the evacuation spaces 511. In this variation, the end 423 of the second partition 422 faces the side portion 424 of the first partition 421 with a predetermined gap left between them. The air passage 600 is the space between the end 423 of the second partition 422 and the side portion 424 of the first partition 421. In addition, the first partition 421 includes a pair of protrusions 426 protruding from the side portion 424 of the first partition 421 such that the pair of protrusions 426 are located on both sides of the end 423 of the second partition 422 along the width of the second partition 422 (i.e., in the upward/downward direction in FIG. 32). Each of these protrusions 426 has a width decreasing as the distance to the second partition 422 decreases. Each of these protrusions 426 has a so-called arc shape. As can be seen, the first partition 421 has a pair of protrusions 426 protruding from the side portion 424 of the first partition 421 toward the end 423 of the second partition 422. In addition, in FIG. 32, the second partition 422 is located between the evacuation spaces 511. Therefore, each of the pair of protrusions 426 faces the end 423 of the second partition 422 and is located closer to associated one of the evacuation spaces 511 than the second partition 422 is. That is to say, in FIG. 32, the upper protrusion 426 is located closer to the upper evacuation space 511 than the second partition 422 is, and the lower protrusion 426 is located closer to the lower evacuation space 511 than the second partition 422 is. As used herein, if a protrusion 426 is located closer to its associated evacuation space 511 than the second partition 422 is, then it means that the center axis X10 of the protrusion 426 is located closer to the evacuation space 511 than the center axis X20 of the second partition 422 is. For example, the center axis X10 of the protrusion 426 may be an axis aligned with a line that divides the protrusion 426 into two along the width thereof. Likewise, the center axis X20 of the second partition 422 may be an axis aligned with a line that divides the second partition 422 into two along the width thereof. In the variation illustrated in FIG. 32, the center axis X20 of the second partition 422 is located between the respective center axes X10 of the pair of protrusions 426.

These protrusions 426, as well as the swollen portion 425, are also able to make the angle defined by the corner portion C10 closer to the angle of intersection (e.g., 90 degrees in this embodiment) between the first partition 421 and the second partition 422 as shown in FIG. 13. This curbs a decrease in the strength at a connecting portion between regions S10, S20 defined by the partitions 421, 422 and a decline in appearance. Optionally, at least one of the pair of protrusions 426 may be located closer to an associated evacuation space 511 than the second partition 422 is. For example, if the second partition 422 is located between an evacuation space 511 and another type of space (which may be either the buffer space 512 or the ventilation space 520), then one of the pair of protrusions 426 is located closer to the evacuation space 511 than the second partition 422 is. That is to say, at least one of the one or more protrusions 426 needs to face the end 423 of the second partition 422 and be located closer to the evacuation space 511 than the second partition 422 is. In that case, the first partition 421 may have only the protrusion 426 that is located closer to the evacuation space 511 than the second partition 422 is. This is because as for the spaces other than the evacuation spaces 511, a decrease in the strength of the boundary walls 42 is not a significant problem.

The protrusions 426 may be formed by moving the dispenser 820 along the path T24 while discharging the material M20 through the nozzle 821. The path T24 includes three paths along three sides of a rectangle to be formed to come temporarily closer toward the end 423 of the partition 422 to form the protrusion 426. That is to say, the application step includes forming the pair of protrusions 426 by locally bringing the dispenser 820 closer toward the end 423 of the second partition 422 while applying the material M20 along a longer side of the first partition 421. Alternatively, the protrusions 426 may also be formed by moving the dispenser 820 along the path T25 shown in FIG. 33 while discharging the material M20 through the nozzle 821. The path T25 includes three paths along three sides of a rectangle to be formed to come temporarily closer toward the end 423 of the partition 422 to form the protrusions 426. That is to say, the application step includes forming the pair of protrusions 426 by locally bringing the dispenser 820 closer toward the end 423 of the second partition 422 while applying the material M20 along a longer side of the first partition 421,

The shape of the protrusions 426 is not particularly limited as long as the protrusions 426 protrude toward the end 423 of the partition 422. In addition, the protrusions 426 need to protrude toward the end 423 of the partition 422 and do not have to overlap with the end 423 along the length of the partition 422. Optionally, the protrusion 426 may be provided as needed for any partition 420 no matter whether the partition 420 is the first partition 421 or the second partition 422. Also, in the fifth variation, the second partition 422 has no swollen portion 425. However, in this fifth variation, the second partition 422 may also have the swollen portion 425 at the end 423 thereof.

Optionally, the protrusion 426 may also be provided for the peripheral wall 410. For example, the end 423 of the partition 422 may face the peripheral wall 410 with a predetermined gap left between them, and the air passage 600 may be the space between the end 423 of the partition 420 and the peripheral wall 410. In that case, the peripheral wall 410 may include one or more protrusions 426 protruding toward the end 423 of the partition 420. In addition, at least one of the one or more protrusions 426 needs to face the end 423 of the partition 420 and needs to be located closer to the evacuation space 511 than the partition 420 is. In particular, the peripheral wall 410 may include a pair of protrusions 426 protruding such that the pair of protrusions 426 are located on both sides of the end 423 of the partition 420 along the width of the partition 420. Note that the protrusions 426 need to protrude toward the end 423 of the partition 420 in question and do not have to overlap with the end 423 along the length of the partition 422. Even in this variation, the partition 420 may also have the swollen portion 425 at the end 423 thereof.

2.1.6. Other Variations

In the embodiments described above, the glass panel units 10 have a rectangular shape. However, this is only an example and should not be construed as limiting. Alternatively, the glass panel units 10 may also have a circular, polygonal, or any other desired shape. That is to say, the first glass panel 20, the second glass panel 30, and the frame member 40 do not have to be rectangular but may also have a circular, polygonal, or any other desired shape. In addition, the respective shapes of the first glass substrate 200, the second glass substrate 300, the peripheral wall 410, the partitions 420, and the reinforcing walls 430 do not have to be the ones used in the embodiments described above, but may also be any other shapes that allow glass panel units 10 of a desired shape to be obtained. Note that the shape and dimensions of the glass panel units 10 may be determined according to the intended use of the glass panel units 10.

The pair of glass panels 20, 30 does not have to have the same planar shape and planar dimensions and does not have to have the same thickness, either. In addition, the pair of glass panels 20, 30 does not have to be made of the same material, either. The same statement applies to the pair of glass substrates 200, 300 as well.

The frame member 40 does not have to have the same planar shape as the pair of glass panels 20, 30 Likewise, the peripheral wall 41, 410 does not have to have the same planar shape as the pair of glass substrates 200, 300, either.

The first sealant of the peripheral wall 410 (peripheral wall 41) and the second sealant of the partitions 420 (boundary walls 42) do not need to include the same core material but may include mutually different core materials. Furthermore, the first sealant may consist essentially of a hot glue. Likewise, the second sealant may also consist essentially of a hot glue. Furthermore, the swollen portion 425 and the protrusions 426 are not essential constituent elements.

Also, in the assembly 100, the peripheral wall 410 is just provided between the pair of glass substrates 200, 300 and does not bond the pair of glass substrates 200, 300 together. Optionally, however, in the assembly 100 stage, the peripheral wall 410 may bond the pair of glass substrates 200, 300 together. In short, in the assembly 100, the peripheral wall 410 needs to be provided between the pair of glass substrates 200, 300 and does not have to bond the pair of glass substrates 200, 300 together.

Furthermore, in the embodiments described above, the air passages 600 are the gaps between the partitions 420 and the imps between the partitions 420 and the peripheral wall 410. However, this is only an example and should not be construed as limiting. Alternatively, the air passages 600 may also be through holes cut through the partitions 420. Still alternatively, the air passages 600 may also be gaps left between the partitions 420 and the first glass substrate 200.

Furthermore, in the embodiments described above, the internal space 500 is partitioned into the plurality of evacuation spaces 511, the plurality of buffer spaces 512, and the single ventilation space 520. However, the internal space 500 may be partitioned by the partitions into one or more evacuation spaces 511, one or more buffer spaces 512, and one or more ventilation spaces 520.

In the embodiments described above, a melting furnace is used to heat the peripheral wall 410, the gas adsorbents 60, and the partitions 420. However, heating may be conducted by any appropriate heating means. The heating means may be a laser beam or a heat exchanger plate connected to a heat source, for example.

In the embodiments described above, the assembly 100 includes a plurality of air passages 600. However, the number of the air passages 600 provided may be one or more. The shape of the air passages 600 is not particularly limited. Furthermore, the assembly 100 needs to include at least one ventilation path P10 and does not have to include a plurality of ventilation paths P10. Furthermore, the ventilation path P10 does not, have to extend along the width of the pair of glass substrates 200, 300 but may extend along the length thereof. In short, the ventilation path P10 may extend in any direction perpendicular to the direction in which the pair of glass substrates 200, 300 face each other. Note that the ventilation path P10 is not an essential constituent element.

In the embodiments described above, the evacuation port 700 is cut through the second glass substrate 300. However, this is only an example and should not be construed as limiting. Alternatively, the evacuation port 700 may be cut through the first glass substrate 200 or may also be cut through the peripheral wall 410 (peripheral wall 41). In short, the evacuation port 700 just needs to be provided to connect the ventilation space 520 to the external environment.

In the embodiments described above, each glass panel unit 10 includes a single gas adsorbent 60. However, the number of the gas adsorbents 60 provided is not particularly limited. Optionally, the glass panel unit 10 may include no gas adsorbents 60 as well. If necessary, the gas adsorbents 60 may be provided in the buffer spaces 512 and the ventilation space 520. Furthermore, the getter of the gas adsorbent 60 is an evaporative getter in the embodiments described above. Alternatively, the getter may also be a non-evaporative getter.

In the embodiments described above, the gas adsorbent 60 has an elongate flat plate shape. However, the gas adsorbent 60 may also have any other shape. In addition, the gas adsorbent 60 does not have to be located at an end of an evacuation space 511. Furthermore, in the embodiments described above, the gas adsorbent 60 is formed by applying a liquid including a powder of a getter (such as a dispersion liquid obtained by dispersing the powder of the getter in a. liquid or a. solution obtained by dissolving the powder of the getter in a liquid). However, this is only an example and should not be construed as limiting. Alternatively, the gas adsorbent 60 may include a substrate and a getter adhered to the substrate. Such a gas adsorbent 60 may be obtained by immersing the substrate in a liquid including a powder of the getter and drying the substrate. Note that the substrate may have any desired shape and may have an elongate rectangular shape, for example. Still alternatively, the gas adsorbent 60 may also be a film formed to cover the surface of the second glass substrate 300 either entirely or only partially. Such a gas adsorbent 60 may be obtained by coating the surface of the second glass substrate 300 with a liquid including a powder of the getter. Yet alternatively, the gas adsorbent 60 may be included in the pillars 70. The pillars 70 including the gas adsorbent 60 may be obtained by making the pillars 70 of a material containing the getter. Alternatively, the gas adsorbent 60 may even be a solid matter made of the getter.

Furthermore, in the embodiments described above, the plurality of pillars 70 are arranged over the entire internal space 500 (i.e., in each of the evacuation spaces 511, the buffer spaces 512, and the ventilation space 520). However, the pillars 70 do not have to be arranged in the buffer spaces 512 and the ventilation space 520. Furthermore, in the embodiments described above, each glass panel unit 10 includes a plurality of pillars 70. Alternatively, each glass panel unit 10 may include a single pillar 70. Still alternatively, the glass panel unit 10 may include no pillars 70 at all.

In the embodiments described above, the evacuation spaces 511 and the buffer spaces 512 are in a vacuum condition, However, the vacuum condition does not need to be created there but a pressure reduced condition may be produced there. As used herein, the “pressure reduced condition” refers to a condition in Which the pressure is lower than the atmospheric pressure.

2.2. Variations of Second Embodiment

FIG. 48 illustrates a glass window 1010A according to a variation. The glass window 1010A includes a glass panel unit 1011, a window frame 1012A, and a plurality of (e.g., four in the example illustrated in FIG. 48) attachments 1013.

The window frame 1012A surrounds the outer periphery of the glass panel unit 1011. The window frame 1012A has a polygonal shape in a plan view. The outer peripheral shape of the window frame 1012A is a polygon having fewer sides than the profile of the glass panel unit 1011. The window frame 1012 has the shape of a quadrangle with four sides in a plan view. In this variation, the outer peripheral shape of the window frame 1012A is square in a plan view. The window frame 1012A has a plurality of (e.g., four in this embodiment) corners 1012 a-1012 d.

Also, the window frame 1012A has an opening 1121 at its center. In a plan view, the opening 1121 has a shape similar to an outer peripheral shape of the window frame 1012A. Thus, the opening 1121 has a square shape. Accordingly, the inner periphery of the window frame 1012A has a plurality of (e.g., four in this embodiment) inner side surfaces 1121 i-1121 l. These four inner side surfaces 1121 i-1121 l respectively correspond to the four sides of the opening 1121 in a plan view In this case, the inner side surfaces 1121 i-1121 l have an equal length. The inner side surfaces 1121 l, 1121 k face each other and are parallel to each other. The inner side surfaces 1121 j, 1121 l face each other and are parallel to each other.

The glass panel unit 1011 is fitted into the opening 1121 of the window frame 1012A. At this time, out of the plurality of side surfaces 1011 a-1011 h of the glass panel unit 1011, the side surfaces 1011 a, 1011 c, 1011 e, 1011 g respectively come into contact with the plurality of inner side surfaces 1121 i-1121 l of the window frame 1012A. In particular, each of the side surfaces 1011 b, 1011 d, 1011 f, 1011 h of the glass panel unit 1011 becomes a facing surface that faces an associated one of the plurality of corners 1012 a-1012 d of the outer periphery of the window frame 1012A.

The attachments 1013 are members for closing the gaps between the inner periphery of the window frame 1012A and the respective facing surfaces (1011 b, 1011 d, 1011 f, 1011 h) of the glass panel unit 1011. In this glass window 1010A, one attachment 1013 is arranged in the gap between the corner portion connecting the inner side surfaces 1121 i, 1121 j and the side surface 1011 b. In addition, another attachment 1013 is arranged in the gap between the corner portion connecting the inner side surfaces 1121 j, 1121 k and the side surface 1011 d. Furthermore, two more attachments 1013 are respectively arranged in the gap between the corner portion connecting the inner side surfaces 1121 k, 11211 and the side surface 11.1 f and in the gap between the corner portion connecting the inner side surfaces 1121 l, 1121 i and the side surface 1011 h. The attachments 1013 may be made of a resin material, for example. The resin material suitably has low thermal conductivity. That is to say, the resin material is suitably a thermally insulating material (i.e., suitably has thermal insulation properties). Optionally, the attachments 1013 may also be hollow members. This would further improve the thermal insulation properties. Furthermore, the attachments 1013 suitably look similar to the glass panel unit 1011. That is to say, the attachments 1013 are suitably no more noticeable than the glass panel unit 1011. If the glass panel unit 1011 is transparent, then the attachments 1013 are suitably transparent as well.

Note that in the variation illustrated in FIG. 48, the number of the attachments 1013 provided is not particularly limited. In short, the glass window 1010A may further include one or more attachments 1013 to close one or more gaps between the inner periphery of the window frame 1012A and one or more facing surfaces (1011 b, 1011 d, 1011 f, 1011 h).

Furthermore, in the glass window 1010 according to the embodiment described above, at least one of the plurality of side surfaces 1011 a-1011 g of the glass panel unit 1011 needs to be a facing surface that faces any one of the plurality of corners 1012 a-1012 d of the outer periphery of the window frame 1012. The same statement applies to the glass window 1010A as well.

Furthermore, in the embodiments described above, in the predetermined part 1112, the space surrounded with the auxiliary frame member 1041 and respective portions, corresponding to the auxiliary frame member 1041, of the pair of glass substrates 1200, 1300 includes the vacuum space 1050. This allows the predetermined part 1112 to be used as a glass panel unit. The glass panel unit 1011 is obtained by removing comers (unnecessary portions 1115) from the glass panel unit consisting of the predetermined part 1112. Thus, the glass panel unit 1011 comes to have the shape of a polygon having more sides than the glass panel unit consisting of the predetermined part 1112. The larger the angle of the comers of the glass panel unit 1011 is, the less likely the glass panel unit 1011 is affected by the warpage of glass (glass panels 1020, 1030) due to heat. This allows the glass panel unit 1011 to further reduce the unbeneficial effect of the warpage of glass (glass panels 1020, 1030) due to heat.

Furthermore, in the embodiments described above, the glass panel unit 1011 has an octagonal shape. However, the glass panel unit 1011 may also have any other polygonal shape. Nevertheless, the glass panel unit 1011 suitably has the shape of a polygon with five or more sides. In addition, the glass panel unit 1011 is not required to have the shape of a polygon in a strict sense but may have somewhat round corners. That is to say, the pair of glass panels 1020, 1030 and the frame member 1040 do not have to have an octagonal shape but may have any other polygonal shape. Note that the shape and dimensions of the glass panel unit 1011 are determined according to the intended use of the glass panel unit 1011. Furthermore, the respective shapes of the pair of glass substrates 1200, 1300 and frame member 1400A of the work in progress 1111 do not have to be the shapes adopted in the embodiments described above but may also be any other shapes that allow the glass panel unit 1011 to have a desired shape. For example, although two glass panel units 1011 are obtained from a single work in progress 1111 in the embodiments described above, either a single glass panel unit 1011 or three or more glass panel units 1011 may be obtained from a single work in progress 1111 as well.

Furthermore, each of the pair of glass panels 1020, 1030 may have a coating with desired physical properties. For example, the coating may be a film that reflects light with a predetermined wavelength (such as an infrared reflective film or an ultraviolet reflective film).

Furthermore, in the embodiments described above, the frame member 1040 is made of a hot glue. Nevertheless, the frame member 1040 may include not only the hot glue but also any other component such as a core material. That is to say, the frame member 1040 needs to include at least the hot glue. The same statement applies to the auxiliary frame member 1041 as well. Furthermore, in the embodiments described above, the auxiliary frame member 1041 is formed using a part of the frame member 1040. Alternatively, the auxiliary frame member 1041 may also be formed to surround the frame member 1040 independently of the frame member 1040.

Furthermore, the air passages 1611, 1612, 1621, 1622, 1630 may also be through holes cut through the sealant 1400. Alternatively, the air passages 1611, 1612, 1621, 1622, 1630 may also be the gaps between the sealant 1400 and the second glass substrate 1300. Note that the number and shape of the air passages are not particularly limited.

Furthermore, in the embodiments described above, the outer parts (i.e., the first, second, third, and fourth outer parts) 1410-1440 and inner parts (i.e., the first, second, and third inner parts) 1450-1470 of the frame portion 1400A are made of the same material. That is to say, the material for the outer parts 1410-1440 and the material for the inner parts 1450-1470 have the same softening point. However, this is only an example and should not be construed as limiting. Alternatively, the material for the outer parts 1410-1440 and the material for the inner parts 1450-1470 may have two different softening points. For example, the material for the inner parts 1450-1470 suitably has a higher softening point than the material for the outer parts 1410-1440. This may make the first melting temperature Tm1 lower than the softening point of the material for the inner parts 1450-1470. This prevents the air passages 1611, 1621, 1622, 1630 from being closed in the first melting step.

Furthermore, in the embodiments described above, a melting furnace is used to heat the sealant 1400. However, this is only an example and should not be construed as limiting. Alternatively, heating may be conducted by any appropriate heating means. For example, the heating means may also be a laser beam or a heat exchanger plate connected to a heat source.

Furthermore, in the embodiments described above, the evacuation port 1700 is cut through the first glass substrate 1200. Alternatively, the evacuation port 1700 may also be cut through the second glass substrate 1300 or through the sealant 1400.

Furthermore, in the embodiments described above, the glass panel unit 1011 includes a single gas adsorbent 1060. However, the number of the gas adsorbents 1060 provided is not particularly limited. Alternatively, the glass panel unit 1011 may have no gas adsorbents 1060 as well.

Furthermore, the pillars 1070 are suitably made of a transparent material. Nevertheless, the pillars 1070 may also be made of an untransparent material if their size is sufficiently small. The material for the pillars 1070 is selected to prevent the pillars 1070 from being deformed in the first melting step, the evacuation step, or the second melting step. Furthermore, in the embodiments described above, the glass panel unit 1011 includes a plurality of pillars 1070. However, the number of the pillars 1070 provided is not particularly limited. Alternatively, the glass panel unit 1011 may have no pillars 1070 as well.

3. Aspects

As can be seen from the foregoing description of the first exemplary embodiment and its variations, the present disclosure has the following first through twelfth aspects. In the following description, reference signs are added in parentheses to the respective constituent elements solely for the purpose of clarifying the correspondence between those aspects of the present disclosure and the first exemplary embodiment described above.

A work in progress (110; 110A) of a glass panel unit according to a first aspect is used to manufacture the glass panel unit. The work in progress (110; 110A) includes: a pair of glass substrates (200, 300) arranged to face each other; a peripheral wall (41) having a frame shape and disposed between the pair of glass substrates (200, 300); a boundary wall (42; 42A); and an evacuation port (700). The boundary wall (42; 42A) is provided to hermetically separate an internal space (500), surrounded with the pair of glass substrates (200, 300) and the peripheral wall (41), into an evacuation space (511), a buffer space (512), and a ventilation space (520). The evacuation port (700) connects the ventilation space (520) to an external environment. The evacuation space (511) and the buffer space (512) have a lower internal pressure than the ventilation space (520). A predetermined part of the work in progress (110; 110A) forms the glass panel unit (10). The predetermined part includes the evacuation space (511) but excludes parts covering the buffer space (512) and the ventilation space (520). The first aspect contributes to increasing the production yield of glass panel units (10).

A work in progress (110; 110A) of a glass panel unit according to a second aspect may be implemented in combination with the first aspect. In the second aspect, the work in progress (110; 110A) of the glass panel unit further includes a plurality of pillars (70) arranged to maintain a predetermined gap between the pair of glass substrates (200, 300). The plurality of pillars (70) are arranged over the evacuation space (511), the buffer space (512), and the ventilation space (520). The second aspect may reduce the chances of, when the work in progress (110; 110A) is being cut off, causing damage to the pair of glass substrates (200, 300) or cutting failures.

A work in progress (110; 110A) of a glass panel unit according to a third aspect may be implemented in combination with the first or second aspect. In the third aspect, the work in progress (110; 110A) of the glass panel unit further includes a gas adsorbent (60). The gas adsorbent (60) is placed in the evacuation space (511), not in the buffer space (512) or the ventilation space (520). The third aspect contributes to improving the thermal insulation performance of the glass panel unit (10).

A work in progress (110; 110A) of a glass panel unit according to a fourth aspect may be implemented in combination with any one of the first to third aspects. In the fourth aspect, a ratio in area of the ventilation space (520) to the internal space (500) is 10% or less. The fourth aspect contributes to increasing the production yield of glass panel units (10).

A work in progress (110; 110A) of a glass panel unit according to a fifth aspect may be implemented in combination with any one of the first to fourth aspects. In the fifth aspect, a ratio in area of the ventilation space (520) to the internal space (500) is 7% or less. The fifth aspect contributes to increasing the production yield of glass panel units (10).

A work in progress (110; 110A) of a glass panel unit according to a sixth aspect may be implemented in combination with any one of the first to fifth aspects. In the sixth aspect, a ratio in area of the ventilation space (520) to the internal space (500) is 2.5% or less. The sixth aspect contributes to increasing the production yield of glass panel units (10).

A work in progress (110; 110A) of a glass panel unit according to a seventh aspect may be implemented in combination with any one of the first to sixth aspects. In the seventh aspect, the buffer space (512 a-512 f) is adjacent to the evacuation space (511 d-511 h). The seventh aspect contributes to increasing the production yield of glass panel units (10).

A work in progress (110; 110A) of a glass panel unit according to an eighth aspect may be implemented in combination with any one of the first to seventh aspects. In the eighth aspect, the evacuation space (511) is not adjacent to the ventilation space (520). The eighth aspect contributes to increasing the production yield of glass panel units (10).

A method for manufacturing a glass panel unit according to a ninth aspect includes: a preparatory step of providing the work in progress (110; 110A) of a glass panel unit according to any one of the first to eighth aspects; and a cutting step of cutting off the work in progress (110; 110A) to obtain the predetermined part (10). The ninth aspect allows a glass panel unit (10) with no evacuation ports (700) to be obtained.

A method for manufacturing a glass panel unit according to a tenth aspect may be implemented in combination with the ninth aspect. In the tenth aspect, the preparatory step includes an assembling step, an evacuation step, and a sealing step. The assembling step includes providing a glass panel unit assembly (100; 100A; 100B; 100C). The assembly (100; 100A; 100B; 100C) includes: the pair of glass substrates (200, 300); the peripheral wall (41, 410); a partition (420); an evacuation port (700); and a plurality of air passages (600). The partition (420) is arranged to partition the internal space (500) into an evacuation space (511), a buffer space (512), and a ventilation space (520). The evacuation port (700) connects the ventilation space (520) to an external environment. The plurality of air passages (600) are provided to evacuate the evacuation space (511) and the buffer space (512) through the evacuation port (700). The evacuation step includes evacuating the evacuation space (511) and the buffer space (512) through the plurality of air passages (600), the ventilation space (520), and the evacuation port (700). The sealing step includes deforming the partition (420) to close the plurality of air passages (600), form the boundary walls (42; 42A), and thereby obtain the work in progress (110; 110A). The tenth aspect allows a glass panel unit (10) with no evacuation ports (700) to be obtained.

A method for manufacturing a glass panel unit according to an eleventh aspect may be implemented in combination with the tenth aspect. In the eleventh aspect, the sealing step includes deforming the partition (420) while evacuating the evacuation space (511) and the buffer space (512) through the plurality of air passages (600), the ventilation space (520), and the evacuation port (700). The eleventh aspect allows the evacuation to be done efficiently.

A method for manufacturing a glass panel unit according to a twelfth aspect may be implemented in combination with the tenth or eleventh aspect. In the twelfth aspect, the evacuation step includes evacuating the evacuation space (511) and the buffer space (512) through an evacuation pipe (830) bonded to the assembly (100; 100A; 100B; 100C). The sealing step includes removing, after having formed the boundary walls (42; 42A), the evacuation pipe (830) while leaving a bonding portion (831) bonded to the assembly (100; 100A; 100B; 1000) and then scraping off the bonding portion (831). The twelfth aspect contributes to increasing the production yield of the glass panel unit (10).

As can be seen from the foregoing description of the second exemplary embodiment and its variations, the present disclosure has the following thirteenth through twenty-sixth aspects. In the following description, reference signs are added in parentheses to the respective constituent elements solely for the purpose of clarifying the correspondence between those aspects of the present disclosure and the second exemplary embodiment described above.

A glass window (1010; 1010A) according to a thirteenth aspect includes a glass panel unit (1011) and a window frame (1012; 1012A). The glass panel unit (1011) has a polygonal shape and includes: a pair of glass panels (1020, 1030) arranged to face each other; and a frame member (1040) arranged between the pair of glass panels (1020, 1030) to hermetically bond the pair of glass panels (1020, 1030) together. The window frame (1012; 1012A) has a polygonal shape and surrounds an outer periphery of the glass panel unit (1011). The glass panel unit (1011) has a plurality of side surfaces (1011 a-1011 h) including at least one facing surface (1011 b, 1011 d, 1011 f, 1011 h) that faces any one of a plurality of corners (1012 a-1012 d) of the outer periphery of the window frame (1012; 1012A). The thirteenth aspect may further reduce the unbeneficial effect of glass warpage due to heat.

A glass window (1010) according to a fourteenth aspect may be implemented in combination with the thirteenth aspect. In the fourteenth aspect, an inner periphery of the window frame (1012) has a plurality of inner side surfaces (1121 a-1121 h) that are respectively in contact with the plurality of side surfaces (1011 a-1011 h) of the glass panel unit (1011). The fourteenth aspect may reduce the backlash of the glass panel unit (1011) with respect to the window frame (1012).

A glass window (1010A) according to a fifteenth aspect maybe implemented in combination with the thirteenth aspect. In the fifteenth aspect, the glass window (1010A) further includes one or more attachments (1013) to close one or more gaps between the inner periphery of the window frame (1012A) and the at least one facing surface (1011 b; 1011 d, 1011 f, 1011 h). The fifteenth aspect may reduce the backlash of the glass panel unit (1011) with respect to the window frame (1012A).

A glass window (1010A) according to a sixteenth aspect may be implemented in combination with the fifteenth aspect. In the sixteenth aspect, the attachment (1013) is made of a resin material. The sixteenth aspect contributes to improving the thermal insulation properties.

A glass window (1010A) according to a seventeenth aspect may be implemented in combination with the sixteenth aspect. In the seventeenth aspect, the resin material is a thermally insulating material. The seventeenth aspect contributes to improving the thermal insulation properties.

A glass window (1010A) according to an eighteenth aspect may be implemented in combination with any one of the fifteenth to seventeenth aspects. In the eighteenth aspect, the attachment (1013) is a hollow member. The eighteenth aspect contributes to improving the thermal insulation properties.

A glass window (1010A) according to a nineteenth aspect may be implemented in combination with any one of the fifteenth to eighteenth aspects. In the nineteenth aspect, the attachment (1013) has the same appearance as the glass panel unit (1011). The nineteenth aspect tends to make the attachment (1013) no more noticeable than the glass panel unit (1011).

A glass window (1010; 1010A) according to a twentieth aspect may be implemented in combination with any one of the thirteenth to nineteenth aspects. In the twentieth aspect, a space surrounded with the pair of glass panels (1020, 1030) and the frame member (1040) is a vacuum space (1050). The twentieth aspect contributes to improving the thermal insulation properties of the glass panel unit (1011).

A glass window (1010; 1010A) according to a twenty-first aspect may be implemented in combination with any one of the thirteenth to twentieth aspects. in the twenty-first aspect, the plurality of side surfaces (1011 a-1011 h) includes a plurality of facing surfaces (1011 b, 1011 d, 1011 f, 1011 h) that respectively face a plurality of corners (1012 a-1012 d) of the outer periphery of the window frame (1012; 1012A). The twenty-first aspect may further reduce the unbeneficial effect of glass warpage due to heat.

A glass window (1010; 1010A) according to a twenty-second aspect may be implemented in combination with any one of the thirteenth to twenty-first aspects. In the twenty-second aspect, the glass panel unit (1011) has the shape of a polygon with five or more sides. The plurality of side surfaces (1011 a-1011 h) respectively correspond to the five or more sides. The twenty-second aspect may further reduce the unbeneficial effect of glass warpage due to heat.

A method for manufacturing a glass panel unit according to a twenty-third aspect includes a preparatory step, a first cutting step, and a second cutting step. The preparatory step includes providing a work in progress (1111). The work in progress (1111) includes: a pair of glass substrates (1200, 1300) arranged to face each other; and a polygonal frame member (1040) arranged between the pair of glass substrates (1200, 1300) to hermetically bond the pair of glass substrates (1200, 1300) together. The first cutting step includes cuffing the work in progress (1111) along a polygon circumscribed about the frame member (1040) to obtain a predetermined part (1112) including the frame member (1040). The second cutting step includes cutting the predetermined part (1112) along the outer periphery of the frame member (1040) to obtain the glass panel unit (1011). The glass panel unit (1011) includes the frame member (1040) and respective portions (1020, 1030) corresponding to the frame member (1040) of the pair of glass substrates (1200, 1300). The twenty-third aspect allows a glass panel unit (1011) with the ability to reduce the unbeneficial effect of glass warpage due to heat to be obtained.

A method for manufacturing a glass panel unit according to a twenty-fourth aspect may be implemented in combination with the twenty-third aspect. In the twenty-fourth aspect, the work in progress (1111) further includes an auxiliary frame member (1041) in the shape of a polygon circumscribed about the frame member (1040). The first cutting step includes cutting the work in progress (1111) along the outer periphery of the auxiliary frame member (1041). The twenty-fourth aspect facilitates the cutting work.

A method for manufacturing a glass panel unit according to a twenty-fifth aspect may be implemented in combination with the twenty-fourth aspect. In the twenty-fifth aspect, the frame member (1040) has the shape of a polygon with five or more sides. The auxiliary frame member (1041) has the shape of a polygon with fewer sides than the frame member (1040). The twenty-fifth aspect facilitates the cutting work.

A method for manufacturing a glass panel unit according to a twenty-sixth aspect may be implemented in combination with any one of the twenty-third to twenty-fifth aspects. In the twenty-sixth aspect, the preparatory step includes an assembling step, a first melting step, an evacuation step, and a second melting step. The assembling step includes providing the assembly (1110). The assembly (1110) includes: the pair of glass substrates (1200, 1300); a first sealant (1401); a second sealant (1402 a, 1402 b); air passages (1611, 1621, 1622, 1630); and an evacuation port (1700). The first sealant (1401) has a frame shape and is arranged between the pair of glass substrates (1200, 1300). The second sealant (1402 a, 1402 b) partitions the internal space (1500) surrounded with the pair of glass substrates (1200) and the first sealant (1401) into a first space (1510) and second spaces (1520). The air passages (1611, 1621, 1622, 1630) connect the first space (1510) and the second spaces (1520) together. The evacuation port (1700) connects the second space (1520) to an external environment. The first melting step includes melting the first sealant (1401) once to hermetically bond the pair of glass substrates (1200, 1300) together with the first sealant (1401). The evacuation step includes evacuating the first space (1510) through the air passages (1611, 1621, 1622, 1630), the second spaces (1520), and the evacuation port (1700) to turn the first space (1510) into a vacuum space (1050). The second melting step includes deforming the second sealant (1402 a, 1402 b) to close the air passages (1611, 1621, 1622, 1630), form the frame member (1040), and thereby obtain the work in progress (1111). The twenty-sixth aspect allows a glass panel unit (11) having the vacuum space (1050) inside but no evacuation ports (1700) to be obtained.

REFERENCE SIGNS LIST

10, 10A-10H Glass Panel Unit

100, 100A, 100B, 100C Glass Panel Unit Assembly

110, 110A Work in Progress of Glass Panel Unit

200, 300 Glass Substrate

41 Peripheral Wall

410 Peripheral Wall

42, 42 a-42 m, 42A Boundary Wall

420, 420 a-420 j Partition

60 Gas Adsorbent

70 Pillar

500 internal Space

511, 511 a-511 h Evacuation Space

512, 512 a-512 f Buffer Space

520 Ventilation Space

600 Air Passage

700 Evacuation Port

830 Evacuation Pipe

831 Bonding Portion

1010, 1010A Glass Window

1011 Glass Panel Unit

1011 a-1011 h Side Surface

1020, 1030 Glass Panel

1040 Frame Menthe

1041 Auxiliary Frame Member

1050 Vacuum Space

1012, 1012A Window Frame

1021 a-1012 d Corner

1013 Attachment

1110 Assembly

1111 Work in Progress

1112 Predetermined Part

1200, 1300 Glass Substrate

1401 First Sealant

1402 a, 1402 b Second Sealant

1500 Internal Space

1510 First Space

1520 Second Space

1611, 1621, 1622, 1630 Air Passage

1700 Evacuation Port 

1. A work in progress of a glass panel unit, the work in progress being used to manufacture the glass panel unit, the work in progress comprising: a pair of glass substrates arranged to face each other; a peripheral wall having a frame shape and disposed between the pair of glass substrates; a boundary wall provided to hermetically separate an internal space, surrounded with the pair of glass substrates and the peripheral wall, into an evacuation space, a buffer space, and a ventilation space; and an evacuation port connecting the ventilation space to an external environment, the evacuation space and the buffer space having a lower internal pressure than the ventilation space, a predetermined part of the work in progress forming the glass panel unit, the predetermined part including the evacuation space but excluding a part covering the buffer space and the ventilation space.
 2. The work in progress of claim 1, further comprising a plurality of pillars arranged to maintain a predetermined gap between the pair of glass substrates, wherein the plurality of pillars being arranged over the evacuation space, the buffer space, and the ventilation space.
 3. The work in progress of claim 1, further comprising a gas adsorbent, wherein the gas adsorbent is placed in the evacuation space, not in the buffer space or the ventilation space.
 4. The work in progress of claim 1, wherein a ratio in area of the ventilation space to the internal space is 10% or less.
 5. The work in progress of claim 1, wherein a ratio in area of the ventilation space to the internal space is 7% or less.
 6. The work in progress of claim 1, wherein a ratio in area of the ventilation space to the internal space is 2.5% or less.
 7. The work in progress of claim 1, wherein the buffer space is adjacent to the evacuation space.
 8. The work in progress of claim 1, wherein the evacuation space is not adjacent to the ventilation space.
 9. A method for manufacturing a glass panel unit, the method comprising: a preparatory step of providing the work in progress of a glass panel unit according to claim 1; and a cutting step of cutting off the work in progress to obtain the predetermined part.
 10. The method of claim 9, wherein the preparatory step includes an assembling step, an evacuation step, and a sealing step, the assembling step includes providing a glass panel unit assembly, the assembly includes: the pair of glass substrates; the peripheral wall; a partition arranged to partition the internal space into an evacuation space, a buffer space, and a ventilation space; an evacuation port connecting the ventilation space to an external environment; and a plurality of air passages provided to evacuate the evacuation space and the buffer space through the evacuation port, the evacuation step includes evacuating the evacuation space and the buffer space through the plurality of air passages, the ventilation space, and the evacuation port, and the sealing step includes deforming the partition to close the plurality of air passages, form the boundary walls, and thereby obtain the work in progress.
 11. The method of claim 10, wherein the sealing step includes deforming the partition while evacuating the evacuation space and the buffer space through the plurality of air passages, the ventilation space, and the evacuation port.
 12. The method of claim 10, wherein the evacuation step includes evacuating the evacuation space and the buffer space through an evacuation pipe bonded to the assembly, and the sealing step includes removing, after having formed the boundary wall, the evacuation pipe while leaving a bonding portion bonded to the assembly and then scraping off the bonding portion. 